A federal judge in Oklahoma has ruled that a sheriff’s deputy violated a woman’s Fourth Amendment rights by using Flock Safety to search for her license plate without a warrant. The judge stated that the deputy should have obtained a warrant, as there was no apparent reason for the search other than the vehicle’s California license plate.

The deputy used the woman’s travel history in Flock as justification for searching her car, where he allegedly discovered 91 pounds of meth. But Judge Sara Hill wrote that all evidence obtained after the Flock search must be suppressed as the fruit of a poisonous tree. The judge’s broader critique of Flock includes concerns about indiscriminate mass surveillance, which she says becomes constitutionally problematic when law enforcement can passively catalog your whereabouts over an extended period and use that information for any purpose whenever convenient.

This ruling adds to a growing chorus of criticism from various quarters, including numerous local and state governments, with Florida and Texas among those that have said they will stop using the technology. On Friday, Senator Bernie Sanders, a Democrat from Vermont, introduced the Block Flock Act, which would bar federal agencies from using automated license plate readers such as Flock. Flock CEO Garretty Langley 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. The company has also reportedly offered voluntary employee buyouts as a way to shrink its workforce.