For months now, we’ve been following the rapid expansion of license plate readers across America. The growth is fueled by federal law enforcement grants that allow for such data to be instantly shared with federal authorities.

We’ve published stories showing how people crossing the US-Mexico border are routinely subject to license plate scans, which is in turn, shared with insurance companies. An intrepid data scientist claimed to have found the location of Minneapolis’ stationary LPRs based on studying public records of the complete log file that he had requested. (Months later, the state law allowing for such access was changed.) As recently as March 2013, Piedmont, a rich Northern California town that is completely surrounded by Oakland, moved toward placing such devices at its entire city border with Oakland.

On Monday, two Californian civil liberties groups filed a lawsuit against the Los Angeles Police Department (LAPD) and the Los Angeles Sheriff’s Department (LASD) in an attempt to compel these agencies to release a week’s worth of automated license plate reader (ALPR, or sometimes, LPR) data from August 2012. The non-profits claim that these agencies are required to do so under the California Public Records Act. In late July 2012, the American Civil Liberties Union and its affiliates sent requests to local police departments and state agencies across 38 states to request information on how LPRs are used.

The American Civil Liberties Union Foundation of Southern California (ACLU) and the Electronic Frontier Foundation (EFF) sought “all ALPR data collected or generated between 12:01 AM on August 12, 2012 and 11:59 PM on August 19, 2012, including at a minimum, the license plate number, date, time, and location information for each license plate recorded.” In its complaint, the ACLU and the EFF allege that the LASD has “not provided Petitioner with any records.”

A spokesperson for the LAPD declined to comment to Ars on the case.

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