EFF and ACLU Ask Appeals Court to Require Warrant for License Plate Reader Searches

The Electronic Frontier Foundation (EFF), a US digital rights group, and the American Civil Liberties Union (ACLU) have filed an amicus brief with the US Court of Appeals for the Sixth Circuit in United States v. Sturdivant. In the case, police tracked a suspect's movements through automated license plate reader (ALPR) data without a warrant. The organizations argue that such tracking is a "search" under the Fourth Amendment to the US Constitution and therefore requires a warrant.

Background of the case

The case stems from a series of robberies in and around Cleveland, Ohio. Surveillance camera footage allowed police to determine the make, model and color of the robber's car, but not its license plate number. After running an open-ended search of two ALPR databases, Flock and ELSAG, officers found that a car belonging to the defendant had been recorded near the robbery sites. This eventually led to his arrest.

The defense moved to suppress the ALPR evidence. The district court rejected the motion, reasoning that Sturdivant had no reasonable expectation of privacy in his license plate number because members of the public can see it. In the court's view, he therefore had no Fourth Amendment interest in avoiding having his car tracked in public places.

EFF's arguments

EFF says ALPRs cannot be compared with noticing a single license plate on a passing car. Its brief describes a vast, interconnected network of ALPRs that continuously track drivers across the country. According to the group, such systems give law enforcement a "virtual time machine" to view the past movements of suspects or anyone else with a single click. EFF has made similar arguments in lawsuits challenging ALPR use in San Jose, California, and in Wisconsin.

The organization also notes that last month a federal district court in another case held that ALPRs are a "form of indiscriminate mass surveillance" that can violate the Fourth Amendment. EFF hopes the Sixth Circuit will reverse the lower court and rule that ALPR searches require a warrant.