EFF asks court: Should cops need a warrant to track your car with license plate scanners?

The Electronic Frontier Foundation (EFF) and the ACLU have filed a legal brief asking a federal appeals court to rule that police should need a warrant to search through Automated License Plate Reader (ALPR) databases. The case involves a defendant in Ohio whose car was tracked near robbery sites using data from two ALPR networks, Flock and ELSAG, after police ran an open-ended search without obtaining a warrant. A lower court previously ruled that the defendant had no expectation of privacy in his publicly visible license plate number.

This legal battle highlights a growing tension between modern surveillance technology and constitutional privacy rights. ALPR systems create vast, interconnected databases that can track a person's movements across time and geography with a few clicks—a capability the EFF argues is fundamentally different from an officer spotting a single license plate. A recent federal court ruling in another case called ALPRs a 'form of indiscriminate mass surveillance.' The outcome of this appeal could set a crucial precedent for how law enforcement uses location-tracking data in the digital age.