LICENSE PLATES FOR DRONES Resolving Privacy Concerns Using Remote Identification Technology Michael Crenshaw

Abstract Cars and airplanes are required to display identifying marks (November numbers and license plates) so

that their drivers can be held responsible for wrongdoing. Now with more registered UAS in the United

States than licensed pilots, it is time to implement a similar rule for unmanned flying devices. The

Federal Aviation Administration (FAA) already requires UAS owners to display registration numbers on

their craft, but many are so small that the numbers could not be read at any significant altitude. The

current rule could theoretically aid prosecution of recklessly-flown UAS that crash, but it will be

ineffective in dealing with reckless flyers who do not crash their devices and those who use their devices

to violate privacy. Therefore the FAA should require UAS to emit a low-power radio beacon identifying

the UAS to anyone within a roughly visual-line-of-sight (VLOS) area.

Keywords: drone, UAS, UAV, privacy, surveillance, license plate, beacon, location services

Contents Abstract ......................................................................................................................................................... 1

Introduction .................................................................................................................................................. 4

Privacy ........................................................................................................................................................... 6

A Brief History ......................................................................................................................................... 6

Status Quo Law ....................................................................................................................................... 7

Privacy and Innovation ........................................................................................................................... 8

Privacy and Free Speech ......................................................................................................................... 8

UAS Technology .......................................................................................................................................... 10

Terminology .......................................................................................................................................... 10

Development ........................................................................................................................................ 11

Applications .......................................................................................................................................... 11

UAS Regulations .......................................................................................................................................... 12

Rules for Commercial Operation .......................................................................................................... 12

Hardware Requirements ................................................................................................................ 12

Operator Requirements ................................................................................................................. 13

Operation Limitations .................................................................................................................... 13

Registration .......................................................................................................................................... 13

Coming Regulatory Changes ................................................................................................................. 14

Remote Identification (Beacon) Technology .............................................................................................. 15

Possible Beacon Implementations ....................................................................................................... 15

Visible Light-Based Beacon (LightCense) ....................................................................................... 15

Airspace Management Beacon (ADS-B) ......................................................................................... 16

Bluetooth Low Energy (BLE) Beacon .............................................................................................. 16

Risk of Spoofing .................................................................................................................................... 17

Policy Recommendation ............................................................................................................................. 18

Authority............................................................................................................................................... 18

Scope .................................................................................................................................................... 18

Use ................................................................................................................................................. 19

Size ................................................................................................................................................. 20

Contents of the License Beacon ........................................................................................................... 21

Implementation and Enforcement ....................................................................................................... 21

UAS Manufacturers’ Role ............................................................................................................... 21

Risks ...................................................................................................................................................... 21

Benefits ................................................................................................................................................. 22

Conclusion ................................................................................................................................................... 23

Introduction Many groundbreaking technologies, when first developed, raise concerns about possible societal

disruptions.1 The rapid emergence of Unmanned Aerial Systems has been no different. Concerns include

weaponization2, smuggling3, and other physical acts of lawlessness. But a more mundane fear has raised

perhaps even more concern: the threat to privacy.

Unmanned Aerial Systems (UAS) have the unique capability to fly low and in some cases even hover for

sustained periods.4 Yet they do not necessarily offer a clear hint of the operator’s identity. UAS may be

equipped with information-gathering technology from simple visible-light cameras to infrared heat

sensors. These devices may scan and store sensitive information about people on the ground, offering

little recourse to those surveilled.

Some UAS are so small that they are undetectable to the naked eye when in flight.5 Even when close

enough to be clearly heard, a UAS’s identifying markings (if any exist) are probably unreadable. This not

only makes UAS potential spying tools, but it makes them particularly dangerous ones because of their

un-detectability and/or anonymity.

In response to concerns of untraceable surveillance activities, privacy advocates have proposed a sort of

remote “license plate” or license beacon for small UAS where the use of a visible identifier would be

impractical.6,7 This paper defends a recommendation for new Federal Aviation Administration

regulations requiring the installation and use of such a beacon on certain UAS. This requirement is

justifiable as a safety measure analogous to the use of tail number on airplanes, but the additional

privacy protection benefits would be significant.

1 Thierer, Adam. Permissionless Innovation: The Continuing Case for Comprehensive Technological Freedom.

Arlington, Virginia: Mercatus Center at George Mason University, 2016.

2 Stanley, Jay. Five Reasons Armed Domestic Drones Are a Terrible Idea. August 27, 2015. https://www.aclu.org/blog/free-future/five-reasons-armed-domestic-drones-are-terrible-idea (accessed July 17, 2016).

3 Valencia, Nick, and Michael Martinez. Drone Carrying Drugs Crashes South of U.S. border. January 23, 2015. http://www.cnn.com/2015/01/22/world/drug-drone-crashes-us-mexico-border/ (accessed July 17, 2016).

4 Though consumer-line UAS usually have under thirty minutes of flight time on one battery charge, advances in battery technology will continue to stretch this limit.

5 Schlag, Chris. "The New Privacy Battle: How the Expanding Use of Drones Continues to Erode Our Concept of Privacy and Privacy Rights." Journal of Technology Law & Policy 23 (2013): 1-22.

6 The call for a license beacon originated with the Center for Democracy and Technology (CDT) in response to privacy concerns. Hall, Joseph Lorenzo. 'License Plates' For Drones? March 8, 2013. https://cdt.org/blog/license-plates-for-drones/ (accessed July 17, 2016).

7 Amie Stepanovich, at the time with the Electronic Privacy Information Center (EPIC), worked with Dr. Joseph Hall of the CDT to further develop his ideas. This paper attempts to pick up where they left off and more fully develop their proposal. Hall, Joseph Lorenzo, and Amie Stepanovich. "License Plates & Drone Information Requirements." Joseph Lorenzo Hall. October 12, 2013. https://josephhall.org/misc/darc-license-plates-session.pdf (accessed July 18, 2016).

The first Part will discuss privacy from both a philosophical and a legal perspective, providing a history

and explaining why it is such a contentious issue. The second Part will describe the current state and

likely future of UAS technology. The third Part will discuss current UAS regulations and gesture toward

changes that will arrive as technology develops. The fourth Part will describe the technologies available

to UAS manufacturers to implement a license beacon. The fifth Part will describe the proposed

regulation along with its benefits, risks, and limitations. The sixth Part will conclude.

Privacy A Brief History Privacy evades definition. When the U.S. Constitution was penned, the meaning of security “against

unreasonable searches and seizures”8 was more obvious. But today information thought of as private is

transferred along wires and through the air, passing among various third parties on its way. Social media

offer outlets for information people are willing to share with a loosely-defined set of “connections” or

“friends,” but not necessarily the whole world. And still people generally expect this information to

remain secure against outside surveillance. The simultaneous expectation for a right to open

communication and to privacy has been wryly dubbed “the privacy paradox.”9

People have worried about technology’s apparent threats to privacy for a long time. In the 1890 Harvard

Law Review article considered the originating document of the “right to privacy,”10 Warren and Brandeis

echo a fear which has resounded through the following decades: “what is whispered in the closet will be

shouted from the mountain-tops.”11

The introduction of the Kodak camera in 188812 raised concerns that it would become “highly

disruptive” to society because of invasions of privacy.13 In the following decades, court rulings and some

legislation worked to mitigate the privacy impact. And many people simply adapted: they developed

norms about when and where photography was acceptable.14

Despite this and other examples of social adaptation to technology, some predict that the notion of

privacy is moving toward obsolescence as a new generation emerges which has never known a world

without pervasive social networking. But there remains a strong contingent of the population which

simultaneously demands the right to broadcast information to whomever they choose while keeping it

hidden from everyone else.15 Some advocate Privacy Enhancing Technologies to counteract privacy-

diminishing technologies.16 Others demand government protection for privacy,17 identifying UAS

8 U.S. Constitution, amend. 4, sec. 1.

9 Jorstad. "The Privacy Paradox." William Mitchell Law Review 27 (2001): 1503-1526.

10 Bratman, Benjamin E. "Brandeis and Warren's The Right to Privacy and the Birth of the Right to Privacy." Tennessee Law Review 69 (2002): 623-651.

11 Warren, Samuel D., and Louis D. Brandeis. "The Right to Privacy." Harvard Law Review 4, no. 5 (1890): 193-

220. 12 Kodak. Milestones. n.d. http://www.kodak.com/ek/us/en/corp/aboutus/heritage/milestones/default.htm

(accessed August 4, 2016).

13 Thierer, Permissionless Innovation, 69.

14 Ibid., 69-70.

15 Numerous special interest groups defend privacy rights, including the Electronic Frontier Foundation, the Electronic Privacy Information Center, the American Civil Liberties Union, and the Center for Democracy and Technology.

16 Wittes, Benjamin, and Jodie C. Liu. "The Privacy Paradox: The Privacy Benefits of Privacy Threats." Brookings. May 2015. http://www.brookings.edu/~/media/research/files/papers/2015/05/21-privacy-paradox-wittes-liu/wittes-and-liu_privacy-paradox_v10.pdf (accessed July 18, 2016).

17 Strahilevitz, Lior Jacob. "Toward a Positive Theory of Privacy Law." Harvard Law Review 126 (2013): 2010-2042.

surveillance as a potential trigger for “another Warren and

Brandeis moment.”18 Many suggest a combination of technology

and regulation (e.g. legal protection for encryption technologies19)

will be necessary to establish sufficient privacy protections.

Though technology will continue to make the dissemination of

information progressively easier, history suggests that people will

continue to demand and develop mechanisms to maintain various

forms of privacy. Therefore, this paper will assume that privacy,

whether technically a right or not, is valuable and important and

should enjoy at least some minimal legal protection.

Status Quo Law There are currently specific laws enumerating corporate responsibilities for protecting consumers’

information. The specific laws, however, are limited to sensitive industries such as banking or

healthcare. This cherry-picking mode of privacy protection contrasts with European omnibus privacy

laws which address privacy violations in whichever sector they appear.20 U.S. federal regulatory agencies

are entrusted with the role of filling in the gaps where the letter of the law does not specifically apply.

The FTC has over the past two decades taken an active role in identifying “unfair” or “misleading” data

security practices and pursuing corrective action against the offending organizations. 21 Data security

entails ensuring information is not accessible to the wrong people; but the FTC is more concerned about

information which has some material value (e.g. Social Security numbers) rather than merely a private

value. Though the FTC does not hold to a full-liability model for data breaches, it will enforce strict

penalties against companies who mishandle customer data. 22

The FCC is stepping further into the realm of data security regulation, taking a more heavy-handed full

liability approach.23 It remains to be seen whether this regulatory regime will support or at least tease

out the implications of privacy for emerging technologies.

Neither the FTC nor the FCC necessarily have authority to determine what information should be private

or how companies should maintain privacy in a technical sense. But both are able to use their statutory

18 Calo, M. Ryan. "The Drone as Privacy Catalyst." Stanford Law Review Online 64, no. 29 (December 2011): 29-

33.

19 For example, the Electronic Frontier Foundation (EFF) has called on the White House to clarify the executive stance on encryption of personal devices such as smartphones. Reitman, Rainey. Where's Obama's Encryption Policy? February 23, 2016. https://www.eff.org/deeplinks/2016/02/wheres-obamas-encryption-policy (accessed July 17, 2016).

20 Strahilevitz, "Toward a Positive Theory of Privacy Law."

21 The Heritage Foundation. Federal Online Data Security Regulation: Where Are We Going? June 28, 2016. http://www.heritage.org/events/2016/06/federal-online-data-security-regulation (accessed July 18, 2016).

22 Ibid.

23 Ibid.

“This paper will assume that

privacy, whether technically

a right or not, is valuable

and important and should

enjoy at least some minimal

legal protection.”

power to determine when companies have behaved irresponsibly and then to pursue corrective

measures.

Privacy and Innovation Some argue that a strict adherence to a strong privacy regime stifles innovation while offering little

benefit in return. For example, massive collections of data are critical to certain emerging business

models, either as the key underlying technology or as a funding mechanism to make a product viable.24

Search engines use past searches to improve personalized results, social networks collect information to

facilitate targeted advertising, and online retailers use past purchases to recommend related products.25

These online features offer a valuable service and may even protect users’ privacy by replacing

undesired human interactions with digital ones.26 However, the sheer amount of personal data revealed

to online services raises serious privacy concerns.

It has been suggested that “psychological” harms such as privacy should receive diminished

consideration when regulators approach new technologies because of the overwhelming benefits of

innovation.27 A hands-off approach may be justified, considering the number of now-commonplace

technologies which initially triggered major fears of societal disruption such as the telephone,

photography, transistors, and location services.28 One could argue by analogy that UAS tech will be far

more self-regulating than the more cautious commentators admit.

However even the champions of innovation identify some exceptional moments when regulation may

be appropriate.29 This paper will argue that certain UAS regulations fit within such an exception and that

some privacy protections are necessary while attempts are made to preserve innovation.

Privacy and Free Speech Demands for privacy have long clashed with demands for free speech. Journalists in particular have

been strong advocates for holding fast to freedom of speech in the face of demands for more strenuous

privacy protections.

UAS have been used by journalists to capture images of everything from natural disaster damage to

costumes of Star Wars characters before the film’s release.30 While some UAS uses by the media have

24 “[T]he collection and analysis of information, facilitated by recent advances in information and

communications technologies, has led to innovation in the operations of firms from online retailers to theme parks to financial services companies.” Goldfarb, Avi, and Catherine Tucker. Privacy and Innovation. Vol. 12, in Innovation and the Economy, by Josh Lerner, & Scott Stern, 65-89. Chicago: University of Chicago Press, 2012.

25 Ibid., 67-69.

26 Wittes and Liu, "The Privacy Paradox: The Privacy Benefits of Privacy Threats," 2-3.

27 Thierer, Permissionless Innovation, 46.

28 Ibid., 68-71.

29 Ibid., 33-35.

30 Kakaes, Konstantin. Drones Can Photograph Almost Anything. But Should They? April 21, 2016. http://www.cjr.org/the_feature/drones_can_photograph_almost_anything_but_should_they.php (accessed July 21, 2016).

seemed more lucrative than others, US case law had erred on the side of protecting the press’s right to

gather and publish information of public interest.

UAS Technology UAS technology is advancing at an amazing rate. Once mostly confined to the R&D departments of

military development organizations31, UAS are now available to everyone from college students to

young children.32 New applications for UAS are emerging constantly as cutting-edge technologies are

fitted for flight. It seems many things that can be done from the ground can be done more effectively

from the air, and things impossible from the ground are now easily accomplished with UAS. This Part will

give an overview of UAS technology, focusing on aspects relevant to privacy concerns.

Terminology Several terms have been used to describe what people generally think of as belonging to the group of

unmanned flying devices. The term drone carries negative connotations due to its association with

legally- and morally-controversial targeted killings by various military

and intelligence organizations.33,34

The term Unmanned Aerial Vehicle (UAV) provides a friendlier

alternative. It refers only to the flying device and not to the supporting

system including remote control(s) and operator(s). The broadest term

is Unmanned Aerial System (UAS), which encompasses not only the

flying device but also its ground support systems.35

The Federal Aviation Administration’s rules for the “Operation and

Certification of Small Unmanned Aircraft Systems” uses all three terms,

but UAS is by far the most frequent.36 This paper will favor using the

term UAS referring to either the UAV alone or the entire UAS.

31 The first remotely-piloted vehicle was flown in 1935. There is a long and steady history of military UAS

development since that time, culminating in their recent roles in the Middle East. Schlag, "The New Privacy Battle,” 3-6.

32 Any number of sources could support the relative ease of obtaining a UAS, but this one is particularly poetic. McKenzie, Bryan. Drones are Here, and not too Expensive. February 17, 2013. http://www.dailyprogress.com/news/local/mckenzie-drones-are-here-and-not-too-expensive/article_4f810398-795e-11e2-b598-0019bb30f31a.html (accessed July 29, 2016).

33 Corcoran, Mark. Drone Wars: The Definition Dogfight. February 28, 2013. http://www.abc.net.au/news/2013-03-01/drone-wars-the-definition-dogfight/4546598 (accessed July 28, 2016).

34 It is the experience of this author that many people are unfamiliar with the more technical terms UAS and UAV. This unfamiliarity, along with the ongoing decoupling of the term drone from negative images, justifies the use of the term in this paper’s title.

35 Corcoran, Drone Wars: The Definition Dogfight.

36 UAS appears in the final rule document 2297 times versus UAV with 52 and drone with 43 (some of those being in reference to organizations with the word drone in their name). While the battle to suppress the term drone appears to be waning, strong preferences remain for the less politically-loaded terms. Federal Aviation Administration, Office of the Secretary of Transportation, and Department of Transportation. "Operation and Certification of Small Unmanned Aircraft Systems." FAA.gov. June 21, 2016. https://www.faa.gov/uas/media/RIN_2120-AJ60_Clean_Signed.pdf (accessed July 28, 2016).

“This paper will use the

term UAS when

referring to the flying

device along with its

support system and

UAV when referring to

the flying device alone.”

Development UAS have enjoyed most of their development and attention as part of military programs, but have more

recently come to the forefront as domestic tools as well.37 Hobbyist model airplane flyers have made an

easy transition from small airplanes and helicopters (which meet the technical definition of UAS) to the

devices more commonly referred to as UAS (such as quadcopters). The wild popularity of inexpensive

hobbyist UAS such as the DJI Phantom series has rushed drones in front of the public eye.

Legal ambiguity38,39 and restrictions40 have so far prevented UAS from entering the commercial sphere in

force. The next Part will discuss regulatory issues in more depth. This Part will focus on commercial

applications which have successfully navigated the regulatory framework and those which have been

proposed for future implementation. It will also discuss some applications and technologies commonly

used among hobbyists, especially insofar as they impact privacy.

Applications As an emerging and quickly-developing technology, UAS applications are surfacing on an almost daily

basis. Many are intuitive and uncontroversial, but some developments have sparked extensive public

debate. Because regulations should account for current UAS applications and anticipate future

developments, this section will highlight some of the more prominent UAS uses and gesture toward

those that appear on the horizon.

37 Schlag, “The New Privacy Battle,” 6.

38 The FAA, while still developing rules for commercial UAS operations, used authority under Section 333 of the FAA Modernization and Reform Act of 2012 to grant waivers to commercial operators. Federal Aviation Administration. Section 333. June 24, 2016. https://www.faa.gov/uas/getting_started/fly_for_work_business/beyond_the_basics/section_333/ (accessed July 30, 2016).

39 “To date, commercial development in the United States, especially among small- and medium-sized enterprises, has been hindered by haphazard FAA rules and regulations and unclear export controls.” Stohl, Rachel, and Shannon Dick. The Feds Just Put the US Back in the Global Drone Race. July 17, 2016. https://www.wired.com/2016/07/feds-just-put-us-back-global-drone-race/ (accessed July 30, 2016).

40 Yadron, Danny. Amazon and Google's Drone Delivery Plans Hit Snag with New US Regulations. June 21, 2016. https://www.theguardian.com/technology/2016/jun/21/amazon-google-drone-delivery-new-faa-regulations-obama (accessed July 30, 2016).

UAS Regulations For some time, UAS operated in a legal gray zone.41 Hobbyists, researches, and developers operated

their UAS without being certain whether they were breaking the law. In 2012, Congress mandated that

the Federal Aviation Administration (FAA) implement new drone rules by 2015 and provide for the

operation of UAS test sites to aid rule development.42 The FAA implemented a UAS registration process

in December 201543 and then released a more comprehensive set of rules in June 2016.44

Rules for Commercial Operation The new rules published by the FAA in June 2016 (“Part 107”) establish the criteria for commercial UAS

operation. Though the ruling does not apply to UAS operated as model aircraft (i.e. for hobby or

recreational use),45 these regulations tend to work as best practices for hobbyist operators.

Hardware Requirements The UAS “must weigh less than 55 lbs. (25 kg).” The rule also applies to UAS as light as 0.55 lbs.46 Smaller

UAS are not explicitly regulated by the FAA and pose little threat to other aircraft.

The FAA requires that the UAS operator inspect the hardware before

each flight.47 The operator must also produce the device for FAA

inspection upon request along with any required paperwork.48

The UAS registration number may be marked on the UAS using “a

permanent marker, label, or engraving.” The marking does not even

have to be externally visible. “[It] may also be enclosed in a

compartment that is readily accessible, such as a battery

compartment.”49 For a small UAS in flight, even external markings may

be difficult or impossible to read for someone on the ground.

41 Stohl and Dick, The Feds Just Put the US Back in the Global Drone Race.

42 FAA Reauthorization and Reform Act of 2012, Public Law 112-95. https://www.gpo.gov/fdsys/pkg/PLAW-112publ95/pdf/PLAW-112publ95.pdf (accessed July 30, 2016).

43 Jansen, Bert. FAA Begins Drone Registry Dec. 21. December 14, 2015. http://www.usatoday.com/story/news/2015/12/14/drone-registry-faa/77275676/ (accessed July 2015, 2016).

44 Dorr, Les, and Alison Duquette. Press Release – DOT and FAA Finalize Rules for Small Unmanned Aircraft Systems. June 21, 2016. https://www.faa.gov/news/press_releases/news_story.cfm?newsId=20515 (accessed July 30, 2016).

45 Federal Aviation Administration et al., "Operation and Certification of Small Unmanned Aircraft Systems,” 68-80.

46 Federal Aviation Administration. "Summary of Small Unmanned Aircraft Rule (Part 107)." FAA.gov. June 21, 2016. https://www.faa.gov/uas/media/Part_107_Summary.pdf (accessed July 30, 2016).

47 Ibid., 2.

48 Ibid., 3.

49 Federal Aviation Administration. "Unmanned Aircraft Systems (UAS) Frequently Asked Questions/Help." FAA.gov. July 15, 2016. https://www.faa.gov/uas/faqs/ (accessed August 1, 2016).

For a small UAS in flight,

even external markings

may be difficult or

impossible to read for

someone on the ground.

Operator Requirements The operator must be at least 16 years old, pass an aeronautical test, and be vetted by the TSA.50

Operation Limitations Because of the FAA’s focus on airspace safety, there are significant limitations on UAS flight.51

UAS may fly a maximum of 400 feet above ground level.

UAS may fly a maximum of 100 mph.

UAS must yield the right-of-way to all other aircraft.

Flight time is limited to daylight hours.

UAS may not fly “over any persons not directly involved in the operation.” (i.e. “No flying over

strangers”)

UAS must always remain within the visual line-of-sight (VLOS) of either the operator or a

designated visual observer.

The VLOS and “no flying over strangers” requirements limit out many useful commercial applications,

such as Amazon’s package delivery ambition.52 Some companies will likely seek waivers for very specific

applications such as linear inspection tasks (e.g. railroads and pipelines).53 But innovation will be limited

for UAS until the VLOS and no-strangers restrictions are lifted.

Registration All UAS operators with devices from .55 to 55 lb. must register with the FAA.54 Recreational operators

must provide their name, address, and email address; and they may operate as many UAS as they want

under one registration.55 Commercial operators must provide the same identification information, but

they must also register each UAS’s make, model, and serial number.56

50 Federal Aviation Administration. "Summary of Small Unmanned Aircraft Rule (Part 107)." 2.

51 Ibid, 1-2.

52 The article cites the “at least one pilot per UAS” rule as another significant barrier, because it prevents automated delivery by a computer system. However, this rule would likely be solved by the same “sense and avoid” technology required to lift the VLOS and “strangers” rules. Yadron, Danny. Amazon and Google's Drone Delivery Plans Hit Snag with New US Regulations. June 21, 2016. https://www.theguardian.com/technology/2016/jun/21/amazon-google-drone-delivery-new-faa-regulations-obama (accessed July 30, 2016).

53 Sievers, Mike. "Small Drone Rules Announced...Now What?" Lexology. June 29, 2016. http://www.lexology.com/library/detail.aspx?g=f940ed22-5b71-4b3a-a484-281149e0850c (accessed August 1, 2016).

54 Federal Aviation Administration. "Getting Started." FAA.gov. July 21, 2016. https://www.faa.gov/uas/getting_started/ (accessed August 1, 2016).

55 Federal Aviation Administration. "Unmanned Aircraft Systems (UAS) Frequently Asked Questions/Help."

56 Ibid.

The UAS operator must have their registration information with them whenever operating their UAS and

must present it to any law enforcement official who requests it.57

As mentioned among the hardware regulations, the registration number must be recorded on the body

of the UAS, though not necessarily on an exterior surface.58 The registration number functions as the

“license plate” or “tail number” for the UAS. Though presumably the registration number would be used

to return a lost UAS to its owner, the registration database is currently not publicly searchable and only

occasionally searchable to law enforcement. Some operators inscribe contact information on their UAS

in case it is lost.

Coming Regulatory Changes John S. Langford, CEO of Aurora Flight Sciences Corporation, said at the 2016 American Institute of

Aeronautics and Astronautics (AIAA) “Demand for Unmanned” convention59 that two barriers remain to

large-scale commercial UAS operation:

1. The development of reliable, affordable detect-and-avoid technology

2. An industry transition from a many-people-per-aircraft-operation model to a many-operations-

per-person model

Technical developments and subsequent regulatory changes will remove both hurdles. Detect-and-avoid

technology is the final step to enabling beyond-VLOS flight. Once that step is taken, privacy advocates

will have no more time to predict issues: their concerns will either materialize or not.

This paper anticipates a time when beyond-VLOS and over-stranger flight will be permissible and

commonplace, because it is at this point that many privacy concerns come into full force.

57 Ibid.

58 Ibid.

59 This author personally attended the convention and made the related notes. There is no publicly-available recording of the cited event at the time of publication. John S. Langford, “Keynote Address” (lecture, AIAA “DEMAND for UNMANNED” Conference, Washington, D.C., June 16, 2016).

Remote Identification (Beacon) Technology A policy recommendation is only as good as the technology which exists to make it feasible. This section

describes the requirements for an effective license beacon implementation and suggests current and

near-future technology which may fit those requirements.

Possible Beacon Implementations A couple attempts have been made to implement license-plate-like tools on UAS, but they have thus far

fallen short. For completeness’ sake, the following sections will first describe the past attempts and then

it will propose a novel solution which may serve as an initial implementation of the recommendation.

Visible Light-Based Beacon (LightCense) Technologists at UC Berkeley have developed a light-based license plate systems for UAS.60 It relies on

an array of LED lights mounted on the bottom of a UAS emitting patterns of differently-colored lights

which may be interpreted by a smartphone app to provide identification information. The creators of

this technology suggest that one could come to learn different UAS light patterns by memory.

The first problem with this technology is its limitation to true visual line of sight. It is reasonable to think

a privacy-conscious individual would be interested not only in the UAS they can see, but the one

hovering just behind a tree in the distance. Radio frequencies pierce more “soft” barriers (such as

foliage), making it a slightly more privacy-conscious technology.

Second, there is a question of whether making UAS more visible is wise. People tend to become hyper-

aware of the privacy threat posed by UAS when they can be heard “buzzing” above.61 Similarly, flashing

visible lights may make people so privacy-conscious that they lose a sense of perspective and make

unreasonable demands in the name of privacy. Similar concerns apply to a lesser extent to radio-

frequency beacons because they are invisible unless explicitly sought using a receiver.

Third, visible lights may be distracting and/or annoying. If UAS regularly fly over highways where drivers’

eyes may be drawn away from the road or perhaps over livestock which may be disturbed, then

LightCense may do more social harm than good.

Finally, Lightcense does not offer much room for expansion. A very limited amount of information may

be transmitted by flashing lights, mostly because smartphone cameras have relatively limited recording

frame-rates: even if the UAS could transmit a very fast series of light flashes, the smartphone could only

receive a limited set of them. And speeding up light transitions would defeat one appealing factor of

LightCense – the idea that a person could identify a light pattern by memory.

Despite these concerns, LightCense offers an excellent proof-of-concept for a license beacon, albeit in a

different area of spectrum. It shows that there is an interest in technologies which make UAS easily

identifiable by someone with no more hardware than a smartphone and no specialized expertise.

60 LightCense. LightCense – A low-altitude identification system for UASs. n.d. http://www.lightcense.co/

(accessed August 1, 2016).

61 Langford, “Keynote Address.”

Airspace Management Beacon (ADS-B) By 2020, all piloted aircraft will be required to operate Automatic Dependent Surveillance-Broadcast

(ADS-B) tracking and collision avoidance technology.62 This is the next generation of airspace

maintenance hardware and software and will take a great step toward making the skies safer.

Some have suggested that ADS-B could be implemented on UAS to provide an identification beacon.63

While this could be practical in the far future, for the moment it is ineffective. ADS-B transmitters are

relatively heavy and would be impractical for small UAS.64 Some very light transmitters are available, but

these are not yet approved by the Federal Aviation Administration (FAA). DJI, the world’s largest UAS

manufacturer, has announced a partnership with uAvionix to develop ADS-B technology for UAS.65 But it

will be some time before that technology is ready for broad deployment.

A secondary issue with ADS-B is that receivers are relatively expensive66 and difficult for non-technical

consumers to operate. Ideally, a license beacon would transmit on a frequency usable by smartphones

so that people of all technical backgrounds could safeguard their privacy.

Bluetooth Low Energy (BLE) Beacon Perhaps the best technology for a license beacon is Bluetooth Low Energy hardware and protocols

designed for location services. Bluetooth emits radio waves in the same bandwidth area as Wi-Fi67 and is

readily interpreted by most smartphone devices.68

Use in Location Services As of Bluetooth 4 (which is widely used as of this writing), low-energy signals may be emitted containing

identifying information about a geographical location such as an area of a store.69 This technology is

under rapid development because of its promise for making geographical areas into troves of

information for smartphones to delve into. The idea behind location services is that businesses may

place beacons in various important places in their stores so that smartphone users may access

62 Federal Aviation Administration. Equip ADS-B. July 28, 2016. https://www.faa.gov/nextgen/equipadsb/

(accessed August 1, 2016).

63 Hall and Stepanovich. "License Plates & Drone Information Requirements." 5-6.

64 Ibid, 12.

65 DJI. DJI And uAvionix To Release ADS-B Collision Avoidance Developer Kit. July 27, 2016. http://www.dji.com/newsroom/news/dji-and-uavionix-to-release-ads-b-collision-avoidance-developer-kit (accessed August 1, 2016).

66 Hall and Stepanovich. "License Plates & Drone Information Requirements." 11-12.

67 Poole, Ian. Bluetooth Radio Interface, Modulation, & Channels. n.d. http://www.radio-electronics.com/info/wireless/bluetooth/radio-interface-modulation.php (accessed August 2, 2016).

68 Bluetooth Special Interest Group. "Bluetooth SIG Analyst Digest 2H 2014." Bluetooth.org. 2014. https://www.bluetooth.org/en-us/Documents/Analyst%20Digest%202H2014.pdf (accessed August 2, 2016).

69 Gruman, Galen. What You Need to Know About Using Bluetooth Beacons. July 22, 2014. http://www.infoworld.com/article/2608498/mobile-apps/what-you-need-to-know-about-using-bluetooth-beacons.html (accessed August 2, 2016).

information relevant to that area. For example, someone walking through a grocery store may be

prompted with coupons for items physically close to where they are standing.

Because beacons operate one-way, privacy concerns are mitigated.70 A smartphone user can receive

information from a beacon without returning any kind of signal and then choose whether to query some

online service to make further use of the beacon’s signal.

Potential Use in UAS Bluetooth beacons may be repurposed to identify not a static (or semi-static) location but to identify a

mobile device. If a smartphone may read a Bluetooth beacon to determine it is physically close to the

pizza isle at a grocery store, then it can read a similar beacon to determine it is physically close to a UAS.

The beacon would be receivable over a roughly line-of-sight area, which is what matters to the privacy-

conscious individual on the ground.

Range Limitations Bluetooth does, by design, have a limited range. However, two factors make it likely that Bluetooth will

be sufficient for current UAS applications. First, altitude greatly increases the range of signal for Wi-Fi

band radios. As a UAS climbs (and captures a greater line-of-sight for its sensors) its beacon will cover a

larger area. Second, rapid development of Bluetooth for location services means there is a demand for

and progress toward longer-range Bluetooth capabilities. The recent announcement of plans for

Bluetooth 5 promise significantly greater beacon range at a much lower power cost.71

Risk of Spoofing There is a risk that UAS beacons may be copied in order to make bad behavior attributable to the wrong

UAS owner. If Bluetooth technology is the chosen technology, then safeguards are already being

developed in the context of location services.72 A number of proposals have been brought forward, with

various strengths and weaknesses; but several are sufficient for the purpose of remote UAS

identification.73

70 Sterling, Greg, Jules Polonetsky, and Stephany Fan. Understanding Beacons: A Guide to Beacon Technologies.

December 2014. https://fpf.org/wp-content/uploads/Guide_To_Beacons_Final.pdf (accessed August 2, 2016).

71 Bluetooth Special Interest Group. Bluetooth 5 Quadruples Range, Doubles Speed, Increases Data Broadcasting Capacity by 800%. June 16, 2016. https://www.bluetooth.com/news/pressreleases/2016/06/16/-bluetooth5-quadruples-rangedoubles-speedincreases-data-broadcasting-capacity-by-800 (accessed August 2, 2016).

72 Hassidim, Avinatan, Yossi Matias, Moti Yung, and Alon Ziv. Ephemeral Identifiers: Mitigatin Tracking & Spoofing Threats to BLE Beacons. April 14, 2016. https://developers.google.com/beacons/eddystone-eid-preprint.pdf (accessed August 2, 2016).

73 Ibid., 2-3.

Policy Recommendation The Federal Aviation Administration (FAA) should require all sUAS to operate a radio frequency beacon

emitting information about the system including, but not limited to, its registration number. The beacon

should use technology commonly available to consumers, preferably at a very low cost. Transmissions

should be receivable in an area roughly matching the visible line-of sight and readable with inexpensive

(preferably commonplace) hardware. A more detailed discussion of this recommendation and

justification for each part follows.

Authority The FAA does not have authority to make rules for the sole purpose of protecting civilian privacy.74 But it

does have authority to ensure the safety of other aircraft and people/property on the ground in case of

UAS failure or mishandling. License beacons could be justified by analogy to tail numbers on airplanes.

But there are several reasons why remote identification is uniquely necessary for UAS safety:

UAS sometimes “fly away.” In case of a loss of communication or some other malfunction, a

UAS may self-pilot somewhere beyond the operator’s immediate ability to retrieve or even

locate it. A license beacon would allow an observer to identify a fly-away UAS and take

measures to return it to the owner’s control.

UAS may cause damage during flight. Small UAS have been referred to as “flying lawn mowers.”

One could fly past or into something vulnerable and then recover and fly away. Outside VLOS,

such a “hit-and-run” could even occur without the operator’s knowledge. In the case of a larger

UAS, something could fall from the device and strike something vulnerable below. In either case,

it would be useful to identify the offending UAS.

UAS may be involved in “near-miss” incidents. A number of apparent UAS near-collisions with

commercial airplanes have been documented. UAS enthusiasts have argued that the airplane

pilots probably misidentified birds. The near-miss statistics have been used as reasons to restrict

UAS development and flight. A license beacon would make it possible to determine whether a

UAS was in the area at the time of the apparent near-miss and even pursue action against the

offending UAS operator.

These three threats to airspace safety are sufficient to warrant FAA action. As one commentator said,

“Privacy is a safety issue.” The FAA does not need explicit authority in matters of privacy to take

common-sense action which will improve privacy.

Scope In the spirit of allowing technological development to occur relatively unimpeded, the scope of this

recommendation will be as narrow as possible while still achieving its intended purpose of guarding

civilian privacy. This recommendation should not be misconstrued as calling for an all-seeing database or

“map” of UAS locations and uses. Rather, the recommendation should be understood solely as meeting

the minimum threshold of letting civilians know what devices are flying immediately above them to allay

privacy concerns.

74 Given the current state of privacy theory and law in the U.S., the FAA probably could not effectively make

privacy-protecting rules even if given explicit jurisdiction in the area.

This recommendation rests on the assumption and seeming reality that the beacon technology it

discusses will not unreasonably burden drone manufacturers. A beacon obviously must take up some

weight, space, and power from the device; ideally the necessary hardware would already be used for

other purposes on the UAS and not require an addition of special hardware.

The beacon may require resources which would otherwise enable some extra feature or application.

This recommendation assumes that the displaced feature(s) would be merely interesting and/or helpful

and not central to the purpose of the UAS. Some sacrifice is necessary, but it should not unnecessarily

hinder technological application and advancement.

Use Not every UAS application lends itself equally to a license plate requirement. Various groups will likely

defend their use of UAS as not significant enough to regulate or as exceptional in such a way as to justify

an exemption.75 This section will pose a few such arguments and attempt to anticipate others that may

arise.

Commercial UAS owned or employed by commercial entities seem to fit the simplest argument for license plating.

Commercial entities have an incentive to capture private information for various purposes. Therefore,

due scrutiny should be applied to ensure companies do not unnecessarily infringe upon privacy,

especially without the public’s knowledge. License plating of commercial UAS is also easily enforceable

within the FAA’s current regulatory scheme because the cost of implementation and maintenance of a

beacon would be far less than the potential cost of non-compliance.

Police Civil rights advocates will likely offer the strongest support for requiring law enforcement UAS license

beacons. Fears have long existed of an all-seeing “Big Brother” form of government from which there is

no hope of privacy. Dystopian fears aside, UAS do offer an inexpensive, effective form of surveillance

which could be abused. Therefore law enforcement UAS on routine

missions should be required to emit a license beacon so that civilians take

their concerns to the authorities if they believe there is misuse.

Law enforcement agencies, of course, have a strong argument for the

necessity of UAS operating with relative secrecy and anonymity. Legitimate

investigative activities may be rendered ineffective if suspects are able to

detect and identify law enforcement UAS from a distance. Some scheme

should be developed by which exceptions to the beacon requirement may

75 For example, the Association of Model Aircraft has opposed any FAA registration process for non-commercial

UAS use, arguing that the FAA’s regulation of “aircraft” does not extend to “model aircraft” and that AMA registration should be sufficient. The AMA Executive Council. Hold Off On Registering. December 17, 2015. http://amablog.modelaircraft.org/amagov/2015/12/17/hold-off-on-registering-model-aircraft/ (accessed July 26, 2016).

“As a general

principle, the risk

calculus should favor

transparency.”

be granted.76 There should also be a system to retroactively grant waivers in emergency scenarios where

typical exemption procedure cannot be effectively followed.

As a general principle, the risk calculus in the waiver process should favor transparency. Only in truly

exceptional circumstances where an operating license beacon would almost certainly jeopardize a

mission should the requirement be waived.

Private Individual, private UAS owners might make the strongest case for an exemption to the license plate

requirement. Private operators are more likely to simply be hobbyists, taking their quadcopter out for a

fun new view of the local scenery. And as long as the UAS is flown within visual line of sight, it is unlikely

that any invasion of privacy will occur (unless the UAS is flown in, for example, a compact neighborhood

where privacy is mostly protected by tall fences).

At the same time, some of the more sensational invasions of privacy are likely to occur as the result of

individuals’ actions. For example, the UAS flown to peer into a Seattle woman’s window appeared to

have been piloted by nosy neighbors and not some commercial interest. Had the woman been able to

collect a reliable identification number for the UAS, she could have pursued legal action against the

offender. An exception for private use would have been negative in this scenario.

But there is also the question of UAS owner privacy. If a hobbyist is flying a UAS in their own back yard

or at a local park, is it really necessary for people in the general vicinity to be able to collect information

about their UAS which may be traceable to the individual? License plates for cars are easily traced by

police, and there is evidence to suggest that civilians may sometimes access information about a car

owner which is only intended for official police business. This could be especially important in the case

of children flying UAS in public spaces risking exposing information such as names and addresses to

strangers.

Finally, there is an important question of enforceability for private UAS operators. Because many UAS

systems are easily modifiable by design (which tends to be a boon for innovation), license beacons could

theoretically be disabled with various ease. Even worse, they could be disabled during some illicit

activity and then re-enabled later, creating an illusion of compliance. High penalties would probably be

the only effective mechanism to ensure compliance, and situations where illegal operation offers high

rewards would not be discouraged by the law alone.

Size Because of the potential weight and power requirements of a license beacon, some consideration may

be necessary for very small UAS. The Technology section above discusses more in-depth which UAS will

likely be capable of carrying this technology.

76 Law enforcement would have to work with manufacturers and regulators to create a “switch” to enable and

disable the beacon. A cryptographic key could be provided by the waiver-granting body to check back abuse of the “off switch.”

Contents of the License Beacon The most basic information which should be included in the beacon’s transmission is the registration

number of the UAS, or another similar number which may be tied to other information such as the

owner’s name, address, corporate affiliation, etc.

It would be convenient to broadcast more information so that people may quickly assess who is flying

UAS over their heads and why. But this too closely approaches violating the privacy and even safety of

the flyer. If someone becomes angry about the use of a UAS over their back yard, it is probably best that

they be required to go to the police to file a complaint rather than going to the UAS owner’s front door.

Also, transmitting too much information may trigger the same issue as noisy or overly-visible UAS

(discussed more in the Technology section): people on the ground may become hyper-aware of the

threat to their privacy and overreact against the technology instead of just the offending party.

Therefore information broadcast should probably be limited to an identification number which law

enforcement may trace to an individual or corporation. The already-required registration numbers for

UAS would serve this role perfectly.

Implementation and Enforcement UAS Manufacturers’ Role UAS designers and manufacturers could simply implement beacons in their devices which are difficult to

disable. DJI, the world’s largest small UAS manufacturer, has built-in geo-fencing technology which is not

technically required by FAA regulations.77 But because it is good practice and improves the public image

of UAS, DJI finds it profitable to include the safeguard.

It is also conceivable that UAS operating systems could be used on a licensing basis where the owner

agrees to follow the manufacturer’s terms of service unless they install a different OS (which most

would probably opt not to do).

Risks This is a very low-risk recommendation, making it an ideal step toward greater safety and privacy

protections in the U.S. The one major risk this author has identified is the potential for hyper-awareness

of UAS curbing innovation. One expert familiar with UAS technology noted that people become most

concerned about their privacy when they can hear a UAS hovering above.78 Similarly, the ability to

detect otherwise-unnoticed UAS via license beacons could give rise to alarmism.

However, a license beacon would be invisible to bystanders who are not already actively concerned

about their privacy. They would have to intentionally use hardware (or install software on their

smartphone) designed to detect and read the license beacon. Therefore this recommendation would

77 Mandatory geo-fencing controls are only activated in areas sensitive for national security reasons. Other areas

require only a “verified” DJI account to override – that is, the operator must provide credit card information. DJI. Geospatial Environment Online. n.d. http://www.dji.com/flysafe/geo-system (accessed July 27, 2016).

78 Langford, “Keynote Address.”

not make bystanders more aware of threats to privacy; rather it would offer a mode of recourse for

those who already feel threatened.

Benefits Besides the safety benefits described in the Authority section, this recommendation would offer a

practical way for people to pursue action against UAS operators who grossly violate privacy. Records of

beacon recordings could be used as strong evidence in criminal cases and law suits against offending

operators. This will take privacy concerns out of the hands of alarmists and place them back where they

belong: in the courts and in the court of informed public opinion.

This greater sense of security with respect to UAS operations could also provide a boost to UAS

development and utilization. As mentioned above, transformative technology usually requires time and

effort to be made palatable to the public. Greater transparency may help allay paranoia and speed

adoption of emerging UAS technology.

Conclusion UAS technology is advancing at such a rapid pace that commercial beyond-visual-line-of-sight operations

could become commonplace in the near future. The advanced sensing and recording technologies

carried by these UAS have risen well-founded concerns among privacy rights groups and activists.

Though the state of privacy theory and law in the U.S. is not such that sweeping privacy regulations

would likely be effective, certain common-sense rules should be implemented to curb rising fears.

Federal Aviation Administration rules requiring implementation of license beacons for UAS covered

under Part 107 would be justified as a safety measure and invaluable as a privacy safeguard. The

technology making this practical either already exists or is within easy reach.

License beacons for UAS would allay privacy concerns by allowing people to identify the devices flying

within their visual line of sight and pursue action against offending operators. This recommendation

would have almost no inflammatory effect in privacy concerns because only those already seeking

protection against snooping would bother to read UAS license beacons. And it would hasten adoption of

UAS technology by mitigating a primary concern among those whom it would affect.

License beacons for UAVs are justified, practical today, and just make good common sense.