When the FBI sent secret spy planes to capture surveillance footage of the Baltimore protests of Freddie Gray's death in 2015, the agency justified the aerial monitoring as necessary. “Large scale demonstrations and protests" meant there was “potential for large scale violence and riots," the agency wrote in an internal memo at the time.
Last week, the FBI released more than 18 hours of this footage in response to a FOIA request from the American Civil Liberties Union. Captured by a thermal-imaging system with infrared cameras mounted to the plane's wing, the footage was taken over five days during at least 10 surveillance flights. The footage shows major Black Lives Matter marches, quiet neighborhood gatherings and near-empty streets. It's unclear if law enforcement acted on this footage in policing the protests.
In the memo, released a few months ago as part of a response to the same FOIA, the FBI refers to the surveillance as "consensual," though the thousands of protestors did not consent.
(By way of explanation the FBI basically chalked this up to a poor choice of drop-down menu options, noting that another pilot had chosen "other" instead. "It wasn't a mistake," a spokesperson said. "It was just two different people used two different options on the drop-down menu. There wasn't really a good option that applied to this.")
Baltimore is not the only place the FBI has deployed its spy planes. In October, FBI director James Comey told Congress that they had flown surveillance aircrafts over Ferguson, Missouri during protests of Michael Brown's death. During the last six months of 2015, the agency employed this kind of surveillance more than 3,500 times, according to a Buzzfeed analysis of data collected by the aircraft-tracking site FlightRadar24.
"If there is tremendous turbulence in a community, it's useful to everybody — civilians and law enforcement — to have a view of what's going on," Comey said of the surveillance, during a House Judiciary Committee meeting last fall. "Where are the fires in this community? Where are people gathering? Where do people need help? And sometimes the best view of that is above rather than trying to look from a car in the street."
Despite indicating internally that the surveillance was in some way "consensual," Comey told Congress the FBI views obtaining permission for this kind of monitoring unnecessary.
"The law is pretty clear that you don't need a warrant," he said.
Comey is referring to 1989 Supreme Court case law, which found that private citizens shouldn't have an expectation of privacy from the sky. As long as a plane is flying in navigable airspace, one can record whatever they want.
"The logic of the Supreme Court is that anybody could be flying through air space with a camera and see what happens without a warrant," Nathan Wessler, the ACLU attorney who filed the FOIA request, told me. "It's a troubling opinion."
When the Supreme Court issued the ruling, it was a different technological era. Allowing police to fly overhead and capture images was a far smaller threat to the Fourth Amendment, which protects against unreasonable search and seizure. Flying a plane over people's heads was not as easy or cheap as it is today and cameras were not nearly as sophisticated. In the footage from Baltimore, faces are not quite visible, but with slightly improved zoom capability and facial recognition technology, police might be able to easily identify someone from above.
"The calculus has changed," Wessler said.
The ACLU worries that such technology could allow police to racially profile protest movements, or to single someone out of a crowd and later arrest them. Even if law enforcement doesn't go so far, Wessler said the mere possibility might prevent people from protesting, or other acts of public expression.
It's not that citizens should (or ever will) be free from the risk of being creeped on—it's about the probability that they might be, and how aware they are of that risk. A photographer standing on the sidelines of a protest is a known quantity, a reality people can see and then choose to contend with. The invisible plane flying overhead is an unknown threat with the ability to take in an enormous amount of information about a very large number of people all at once. It is a risk that is impossible to quantify because you can never really be sure whether it's there. (To this point, the ACLU actally considers surveillance flights at night bigger invasions of privacy.)
When I asked the FBI about Wessler's assertion, an agency spokesperson reiterated Comey's remarks to Congress.
“As the videos clearly demonstrate, the aviation surveillance was intended to identify areas of potential violence or criminal activity in support of the Baltimore Police Department," they said. "There is no identification or tracking of lawful protesters.”
The questions that need asking go beyond whether or not to allow surveillance of the public from the sky. What kind of data is law enforcement gathering? Who are they sharing it with? How long are they keeping the footage? And are they disclosing their surveillance to the public?
"We're certainly not saying the FBI should never be allowed to use a camera attached to an aircraft," Wessler said. "But when we start seeing hours-long surveillance of people protesting in the streets, that gets worrisome."
The law, of course, always lags behind technological advancements. But as new technologies come into play, the Supreme Court has begun to consider changing in order to protect the integrity of the Fourth Amendment. In 2001, the court found that police could not use thermal imaging to monitor inside someone's home without a warrant, even from a public vantage point.
The court may eventually find that surveilling protestors similarly violates an expectation of privacy.
"We really need to think about what uses of this technology is appropriate," Wessler said, "and what kinds of limitations should be put in place."