Your location data is your life, and police want it all

In the ongoing debate about government surveillance, officials often describe mass data collection as an innocuous or even banal activity. In 2012, news reports revealed how automatic license plate readers (ALPRs) mounted to police cars, lampposts and highway overpasses are tracking millions of vehicle movements daily, capturing geotagged and time-stamped photos of motorists as they traverse the nation’s roadways. But authorities claimed that because license plate photos aren’t “personally identifiable,” collecting them helps catch criminals and dole out speeding tickets without infringing on people’s privacy.

Further, police argued, Americans do not have a reasonable expectation of privacy when driving on public roads. It’s an argument that suggests anything you do in public is fair game for surveillance — and that there’s no difference between a police officer writing down your license plate number and a camera capturing it automatically.

These arguments don’t stand up to scrutiny: License plates are purposefully linked to Americans’ identities, and data about their location over time can provide a remarkably clear picture of a person’s private activities, interests and associations. But as of last week, we know that not only has the Drug Enforcement Agency been spying on millions of drivers for years as part of a plan to build a nationwide vehicle tracking system but also that its ALPR database routinely captures photos of vehicles’ occupants in addition to plates.

That’s a feature, not a bug. According to DEA documents obtained by the American Civil Liberties Union through a Freedom of Information Act request, the cameras capture “vehicle license plate numbers (front and/or rear), photos of visible vehicle occupants [redacted] and a front and rear overall view of the vehicle.” The database stores “up to 10 photos per vehicle transaction, including four occupant photos.” Altogether, the documents suggest Americans are already in the grips of a system designed to record and catalog their every move without any suspicion of wrongdoing.  

ALPRs are already used in virtually every major U.S. city, with some systems boasting the ability to capture up to 1,800 plates per minute. Worse, most agencies still do not have policies governing how long these photos may be retained. Depending on who stores them, it can be anywhere from 48 hours to five years, sometimes even indefinitely.

Private companies are helping fill in the gaps, offering law enforcement agencies access to their massive license plate databases under strict nondisclosure agreements. The largest, held by California-based Vigilant Solutions, boasts more than 2 billion vehicle movement records. According to a Vigilant press release from December, its database uses facial recognition to identify drivers and passengers who appear in license plate photos. That data feeds into the Federal Bureau of Investigation’s nationwide facial recognition database, which sometime this year is expected to amass as many as 52 million face images.

In concert, these technologies function completely counter to our normal conceptions of public space. A system that automatically tracks the movements of millions of Americans without any suspicion is not about stopping crime; it’s about tracking everyone so that laws can be retroactively and selectively enforced. In an age in which police seize hundreds of millions of dollars in cash and property from motorists without any charge or reason, the implications are consequential and chilling.

In 2012, the same year ALPRs first made major headlines, the Supreme Court ruled that police must obtain a warrant before monitoring a suspect’s vehicle with a GPS tracking device. Many saw this as a victory against the normalization of unwarranted police tracking, but in practice it was hardly a deterrent. That’s because at issue was not the tracking itself but the physical placement of a tracking device on the suspect’s car, which the court ruled constituted trespass under the Fourth Amendment.  

Thus police were left with countless other ways of tracking Americans’ movements — in bulk, without any suspicion of crime and without having to be physically present. For example, because of a 1986 data privacy law that exempts data held by third parties from Fourth Amendment protection, cops may conduct so-called tower dumps to access the time-stamped location data of all devices connected to carrier-controlled cellphone towers.

Police also use stingray cellphone interceptors, secretive devices that retrieve the locations, unique identifiers and text messages of every phone in range by mimicking the signal of a legitimate cell tower. As if that weren’t enough, federal agents have been mounting stingrays on planes to widen their data dragnets.

When authorities use these technologies under the excuse that you have no reasonable expectation of privacy in public, they are also asserting that you have no reasonable expectation of anonymity. There is a huge difference between the two, and it’s crucial to recognize just how radical a departure their practices are from how we traditionally move and communicate in public space.

For the purpose of this argument, I’m defining privacy as the ability to conceal communications, movements and transactions and anonymity as the ability to remain unidentified in the course of those activities. Achieving the first in a public space is much harder than the latter. Anyone nearby can see or hear what another person is saying or doing.

But we take for granted that we can walk or drive down the street without being identified. In large cities, we have always strolled through crowded streets, confident that no one can infer anything about us beyond what our physical appearance and mannerisms suggest. But when our streets are polluted with license plate scanners and face recognition cameras, this normative dynamic is perverted. When everyone is identified, each individual wears his past and present actions like a jacket for authorities (or anyone with the right set of sensors) to see and scrutinize. 

Privacy advocates anticipated this growing invasiveness, and some have made efforts to resist it. In 2012, countersurveillance artist Adam Harvey designed Face Dazzle, a makeup scheme that confuses face detection algorithms, making wearers effectively invisible to machines — with the ironic side effect of making them much more visible to humans. Other projects such as noPhoto have tried to do the same for ALPRs, obscuring plates by triggering a bright flash when the traffic camera’s red light is detected.

Policy solutions are needed — specifically, a federal ban or limit on data retention for ALPRs and facial recognition, measured in hours or days rather than months or years, and a warrant requirement for accessing that data. Members of Congress should pass a recently proposed bill that would prevent police from accessing stored emails and location data without a warrant.

Without these precautions, we are headed toward a future in which a transparent citizenry is subject to the rule of opaque and unaccountable law enforcement. Our movements will be monitored, and our past actions will collapse into the present the moment we walk outside.

The appeals court that heard the GPS tracking case said it best (PDF):

A person who knows all of another’s travels can deduce whether he is a weekly churchgoer, a heavy drinker, a regular at the gym, an unfaithful husband, an outpatient receiving medical treatment, an associate of particular individuals or political groups — and not just one such fact about a person, but all such facts.

Location data isn’t some hazy abstraction of your life; it is your life, and the government has no business recording it without a warrant.