A Supreme Court warrant ruling just became a problem for 113,000 police cameras

Police cameras across the United States photograph every license plate that passes them, around the clock, logging the movements of millions of drivers who are not suspected of anything. A Supreme Court ruling on a different technology — cell phone location data — just handed lawyers the legal argument to challenge all of them.

Flock Safety is the dominant player in this market. More than 113,000 automatic license plate readers operate nationwide; the majority come from Flock, with Axon and Motorola Solutions covering much of the rest. In hundreds of cities, these cameras record every passing car and retain the data in searchable databases that law enforcement can query by plate, make, or location. Flock Safety describes the system as a community safety network. Critics describe it as mass surveillance infrastructure.

The Supreme Court’s Chatrie ruling invalidated a police tactic called a geofence warrant — demanding from companies like Google the location data of every mobile phone within a defined geographic area at a specific time, without naming any suspect. The Court ruled 6-3 that this constitutes a dragnet search of people innocent of any crime, violating the Fourth Amendment. The legal principle is structural: the government cannot harvest location data about everyone who happened to be somewhere, without individualizing its suspicion first.

Experts say the same structural question applies to automatic license plate readers. Every time a car passes a Flock camera, the plate is logged — whether the driver is under investigation or simply commuting. The scale mirrors a geofence: bulk collection of innocent people’s movement data, without individualized suspicion, retained for later retrieval. The argument now in legal circulation is that if the government cannot do this digitally with a cell phone, it may not be able to do it physically with a camera mounted on a pole.

Flock Safety has its own legal position. The company cited a separate federal court ruling earlier this year affirming that automatic license plate readers are constitutional — a decision that pre-dates Chatrie. The Supreme Court’s ruling addressed digital location data stored in the cloud, not cameras capturing images in public space, and the distinction may matter legally. Flock’s cameras photograph vehicles on public roads where there is no expectation of privacy, a long-established Fourth Amendment principle that complicates direct application of Chatrie.

The eighty-two jurisdictions that canceled ALPR contracts or removed cameras did so in the weeks following the Chatrie decision. Others are waiting for courts to test the ruling’s logic directly against license plate reader data. That litigation is underway but unresolved. The Chatrie case was decided in late June; courts applying its logic to ALPRs will take months to years to work through the system. What the ruling did immediately is shift the legal landscape: the argument that now exists in Supreme Court precedent did not exist before.

Tags: privacy, Supreme Court, ALPR, Flock Safety, license plate readers, surveillance