A Defense Department slide showing the development of aerial surveillance systems.

The following is an abbreviated version of “Preventing an Air Panopticon: A Proposal for Reasonable Legal Restrictions on Aerial Surveillance,” published in the Volume 51 Spring Edition of the University of Richmond Law Review.  

Imagine a world where a small plane flies miles above a city, effectively invisible to its inhabitants while looking down on them in close detail.  Meanwhile, a series of drones, flown in a semi-automated pattern by a single operator, hover over the surrounding suburbs.  A select group of monitors—no more than a dozen members of the local police force—pinpoint areas of interest in real time, including a large protest, several doctors’ and lawyers’ offices, and a mosque.  These officers are able to zoom in from cameras on the high-flying aircraft to identify individuals by their faces and log their activities. Meanwhile, a small group of federal agents review footage from these planes recorded over the course of the last sixth months, creating a precise map of the movements of hundreds of “persons of interest” over that entire period, and cataloging the places they visited and people they interacted with.

We cannot rely on technological limits to avoid this “Air Panopticon,” in fact we are already far closer to it than many realize.  Many technologies are upending how we view the Fourth Amendment, and the limits it must place on surveillance to maintain a democratic society.  Aerial surveillance has become such an area of upheaval, necessitating an updated standard to protect privacy.

Aerial surveillance has been expanding for years, with a significant number of drones already deployed by law enforcement for domestic surveillance.  Last year domestic aerial surveillance took another leap forward when the Baltimore police contracted a military-grade aerial surveillance vendor, Persistent Surveillance to monitor large swaths of their city.  This firm, which began operating urban aerial surveillance to aid the American military in Iraq, flies multiple Cessna planes at a height of roughly 8,500 feet to watch over “an area of roughly 30 square miles and continuously transmit real-time images to analysts on the ground.”  The program is capable of monitoring virtually the entire city, and can hone in on a particular area as narrow as a street corner.  Persistent Surveillance hopes the program in Baltimore will serve as a model that will be employed in cities throughout the country in the future.

This is all the more worrisome given the growing power of photo zoom and resolution technology.  For example, the Aeryon HDZoom30 – a high-resolution camera for law enforcement and commercial uses – can zoom in and achieve a precise visual identification from 1,000 feet, capable of taking photo and video that can read a license plate or recognizably view an individual’s face.  Yet this pales in comparison to the power of military-grade technology that might one day be used for domestic aerial surveillance.

The Autonomous Real-Time Ground Ubiquitous Surveillance-Imaging System (“ARGUS-IS”) is a DARPA developed video recording technology is in a class all its own.  The field of view it obtains is immense; at full altitude, using a drone-mounted camera-pod aptly named Gorgon Stare, roughly half the size of Manhattan, with full precision — able to “resolve details as small as six inches from an altitude of 20,000 feet.”  Critically, this is not a zoom function where the field of view is narrowed to obtain precision. With the ARGUS-IS, the resolution is so strong that this extreme level of magnification exists continuously throughout the entire field from the far-off 20,000-foot distance.  This means that no zoom and corresponding loss of field of view is required to obtain this extreme degree of intimate surveillance – monitors can look with extreme prevision at different areas of the field simultaneously, or go and look at the most exact point anywhere in the entire area.

Aerial surveillance can also be aided by “tagging technologies,” i.e., technologies that can identify individuals in an automated manner based on unique traits.  Two particular tagging technologies, license plate readers and facial recognition technology, are increasingly used by law enforcement.  With sufficient resolution, an automated system could track the path of thousands of persons or cars without any human effort. More disturbingly, tagging technologies could allow aerial surveillance to surreptitiously focus on a specific site – such as a protest, political rally, or religious center – and monitor all attendees, creating serious danger to First and Fourth Amendment rights.

However regulating tagging technologies would not fully alleviate the threat aerial surveillance poses.  Aerial surveillance encompasses an incredibly wide field of view, and even without a full zoom capable of visual identification, once a target is identified, the aircraft’s camera can follow the path of the particular individual in low resolution.  In fact this is a feature that Persistent Surveillance highlights as a selling point for its services, boasting that its systems “can show you everything that has happened and track the suspect(s) where they go.”

And if the ARGUS-IS or equivalent technology moves into the realm of law enforcement, aircraft could simply fly it at a high altitude of 20,000 feet, and record an entire urban area with precision.  Police could freely zoom in to specific locations—a street corner, office entrance, crime scene, meeting of interest, public demonstration, or backyard—and identify individuals. It could track identified individuals as they traverse a city, log visits, or interact with others.  If equipment comparable to the ARGUS-IS becomes standard issue for law enforcement – as military tools often do – it could well mark the end of anonymity.

To his credit, Persistent Surveillance CEO, Ross McNutt, has insisted he will not allow his program to be used in such an invasive manner, and that his company would widen viewing area rather than enhance resolution.  However, the fact that “[h]e’s exasperated when his system is criticized not for what it does, but for its potential” seems unfairly dismissive of the system’s risks. Persistent Surveillance has set the precedent, and even if this company is unwilling to augment its capabilities, others surely will.

Such powerful surveillance technology may not only be directed at wrongdoers, but abused to target minorities and dissenters.  In recent years, law enforcement has targeted Muslim communities and Black Lives Matter protesters.  And while such conduct has received criticism, it shows no signs of abating. During the 2016 election, President Trump called for surveillance of mosques on numerous occasions, and said he would direct the Attorney General to investigate Black Lives Matter activists.  During his confirmation, Attorney General Jeff Sessions refused to rule out using advanced surveillance technologies to target and catalog individuals engaging in protests, religious activities, or political rallies.

In the wake of these risks, we need a more detailed Fourth Amendment standard for aerial surveillance.  And while the common conception of current law is that the Fourth Amendment does not limit aerial surveillance, the controlling case, California v. Ciraolo, could provide the foundation for an updated rule.  In Ciraolo, the Court held, “t]he Fourth Amendment simply does not require the police traveling in the public airways at this altitude to obtain a warrant in order to observe what is visible to the naked eye.

We should build from this standard, looking at aerial surveillance as a continuum, not a monolith, and at modern aerial surveillance techniques as distinct from the “naked eye” surveillance that occurred in Ciraolo.  Modern aerial surveillance is fundamentally different than that described in Ciraolo, just as a police tail is from the GPS tracking in Jones, and just as a briefcase is fundamentally different from the cellphone in Riley. In all these cases, modern technology has created a situation, unforeseeable in light of the original Fourth Amendment doctrine, which unbalances government power and maintenance of privacy necessary for democratic society.

A “Naked Eye Rule” would build upon Ciraolo by requiring court approval unless the surveillance is akin to a human’s naked eye view from the aircraft.  Such a rule would be consistent with Ciraolo, prevent the type of omniscient aerial surveillance technology is rapidly moving towards, and still meet practical needs: law enforcement could freely engage in low-altitude surveillance, such as with police helicopters or employ more invasive aerial surveillance so long as they demonstrate appropriate cause to a court.  Further, existence of other search exceptions – such as exigent circumstances – would account for critical and emergency needs.  And a rule limiting law enforcement use would not inhibit other government activities, such as using drones to help map and combat wildfires.

Far too often technology outpaces law, with costs to civil liberties in the interim. We are already moving into such a void with regard to aerial surveillance, and it appears the resulting harms to privacy will only continue to grow. The concept of the Naked Eye Rule can act as a step forward towards restoring a balance of law and technology, but there is a formidable amount of discussion, debate, and action that must be undertaken to address the privacy issues examined here. Hopefully, we will work to do so.

Images: US Dept. of Defense