California Police Have Been Illegally Sharing License Plate Reader Data

Some of California’s largest police departments have been collecting millions of images of drivers’ license plates and sharing them with entities around the country—without having necessary security policies in place, in violation of state law, according to a newly released state audit.

The audit, published Thursday, found that 230 police and sheriff’s departments in the state currently use automated license plate readers (ALPRs), which can be fixed cameras or devices mounted on patrol cars. Police have touted the technology as necessary for enforcing parking and basic municipal laws, and as a vital tool in child abduction cases and other high-profile investigations.

The Los Angeles Police Department, for example, has collected more than 320 million images over the last several years. Only 400,000 of those generated immediate matches to cars of interest, but the remaining 99.9 percent of the images, which can be used to track peoples’ movement across the city, stay stored in a department database for more than five years, according to the audit.