A US judge rules an officer's use of Flock to search a car's license plate was a form of "indiscriminate mass surveillance", and violated the Fourth Amendment (Jason Koebler/404 Media)

A US judge has ruled that a police officer's use of Flock, an automated license plate reader system, to search a car's license plate without a warrant was a form of "indiscriminate mass surveillance" and violated the Fourth Amendment. The officer had searched the license plate simply because it was from California and then used the vehicle's travel history as part of the reason to search the car.

The judge, Sara Hill, wrote that the officer's use of the system was an unconstitutional warrantless search, not supported by probable cause. According to 404 Media, there are currently over a hundred thousand warrantless searches of the Flock system every month.

The ruling, one of the first of its kind, implies that law enforcement officers should obtain a warrant before searching for a vehicle in Flock's system. However, the decision will not set a binding precedent, and several other cases considering the legality of warrantless ALPR searches are ongoing throughout the nation.

Brief written by urgent.news from Techmeme, 404 Media — 2 reports on this story. Machine-written — may contain errors; check the original before relying on it.