A federal judge ruled this week that a Tulsa, Oklahoma sheriff’s deputy violated a woman’s Fourth Amendment rights when using Flock Safety to search for her license plate without a warrant. 

As reported by 404 Media, this ruling does not create a binding precedent, but it is one of the first times that a federal judge has ruled that a Flock search is unconstitutional.

In this case, Judge Sara Hill said the deputy should have obtained a warrant before searching the Flock database for the woman’s license plate, as he had “no apparent reason” for the search “other than the fact that [the woman’s vehicle] had a California license plate.”

The deputy then used the woman’s travel history in Flock as part of the justification for searching her car, where he allegedly discovered 91 pounds of meth. But Judge Hill wrote that all evidence obtained after the Flock search “must be suppressed as the fruit of a poisonous tree.”

Judge Hill also took broader aim at warrantless searches of the Flock database, writing that tracking people’s location — even when they’re in public places — becomes “constitutionally problematic when law enforcement can indiscriminately and passively catalog your whereabouts over an extended period of time and then use that information for any purpose whenever convenient.”

“This is a type of indiscriminate mass surveillance,” Hill wrote. “It is not targeted on a single individual, as in [Carpenter v. United States, a Supreme Court case focused on how government agencies access location data from cell phones]. It is a tool that collects information about all vehicles that pass by any network-connected camera at all times, and it serves up the information to law enforcement on demand.”

Hill joins a growing chorus of Flock critics from across the political spectrum. Numerous local and state governments, including Florida and Texas, have said they will stop using the technology. And on Friday, Senator Bernie Sanders introduced the Block Flock Act, which would bar federal agencies from using automated license plate readers such as Flock.

Flock CEO Garrett Langley — who we’ll be interviewing on-stage at TechCrunch Disrupt — has called for a “compromise” between privacy and safety and offered an apology to women who have been stalked by law enforcement officers using the Flock system. And with all those cancellations, Flock has also reportedly offered voluntary employee buyouts as a way to shrink its workforce.