Privacy Groups Push Appeals Court to Require Warrants for License Plate Tracking

The Electronic Frontier Foundation and the ACLU submitted an amicus brief today to the Sixth Circuit Court of Appeals in United States v. Sturdivant, challenging law enforcement's warrantless use of Automated License Plate Reader (ALPR) data to track a suspect's location. The brief contends that the nationwide system of interconnected ALPRs that continuously monitor drivers constitutes a "search" under Fourth Amendment protections.

The case stems from a string of robberies near Cleveland, Ohio. Police used video surveillance to identify the vehicle's make, model and color but lacked the license plate number. Officers then conducted an unrestricted search across two ALPR databases—Flock and ELSAG—and discovered that a vehicle registered to the defendant had been detected near robbery locations, ultimately resulting in an arrest. When the defendant moved to suppress the ALPR evidence, the district court ruled that he had no reasonable expectation of privacy in his license plate number since it is visible to the public, and therefore had no Fourth Amendment protection against tracking in public.

The privacy groups argue that this reasoning misses a fundamental distinction. ALPRs operate on an entirely different scale than spotting a single license plate on a passing vehicle. According to the EFF, which has challenged ALPR deployments through amicus briefs and direct litigation in San Jose, California and Wisconsin, the technology enables law enforcement to "a virtual time machine to view suspects', or anyone else's, past movements (and much more) with just the click of a button." A federal district court recently reached a similar conclusion, characterizing ALPRs as "a form of indiscriminate mass surveillance" capable of violating Fourth Amendment rights.

The EFF and ACLU are urging the Sixth Circuit to reverse the lower court's decision and establish that ALPR searches must be supported by a warrant.