Civil liberties groups urge Sixth Circuit to demand warrants for plate-reader searches

EFF and the ACLU argue that searching license-plate databases to trace a driver's movements is a Fourth Amendment search. The appeal is pending.

The Electronic Frontier Foundation and the ACLU have filed an amicus brief in the Sixth Circuit Court of Appeals in United States v. Sturdivant. They argue that tracking a person through Automated License Plate Reader (ALPR) data is a search under the Fourth Amendment, so police should need a warrant first.

The case comes from a series of robberies in and around Cleveland, Ohio. Police had surveillance footage showing the make, model and color of the robber's car, but no plate number. Without a warrant, officers ran an open-ended search of two ALPR databases, Flock and ELSAG. The search showed a car belonging to the defendant near the robbery sites, and that led to his arrest. He moved to suppress the evidence. The district court denied the motion. It reasoned that a plate number is visible to the public, so he had no reasonable expectation of privacy in it and no Fourth Amendment interest in avoiding tracking in public.

The brief's counterpoint is about scale. It describes a large, interconnected national network of ALPRs that continuously record drivers' movements. Searching it is a different act from one person noticing a plate on one street. For security, the question is whether ordinary movement through public space can be logged and searched at will. A warrant requirement would put a judge between police and that location history. That also protects the commons, since public roads stay usable without being turned into a monitored grid.

The Sixth Circuit has not ruled, and this account comes from an advocacy group describing its own brief. EFF also points to its suits over ALPR use in San Jose, California and in Wisconsin. It says a federal district court ruled last month that ALPRs are a form of indiscriminate mass surveillance that can violate the Fourth Amendment. It does not name that court. Watch for the Sixth Circuit's decision, and for whether other courts follow the same reasoning.

Source: EFF Deeplinks