In a move forcing the law enforcement agencies to be more transparent, the state Supreme Court announced that the Los Angeles Police Department and LA County Sheriff’s Department make public license plate information acquired from automated license plate readers (ALPRs).

The LA County Sheriff’s Department refused to turn over the data to the American Civil Liberties Union (ACLU) and claimed that the millions of files were part of investigations.

“This is a big win for transparency in California,” said Attorney Peter Bibring, director of police practices at the ACLU of Southern California.

The ruling comes after the Pasadena City Council’s Public Safety Committee discussed the use of drones and gunshot location software. At a recent separate meeting, committee members instructed city staff to return with a better report regarding a local software agency. Spokeo Software enables law enforcement investigators to connect to over 12 billion records, 300 million people profiles, more than 95 social media platforms and all public data.

In the lawsuit against the LAPD and the Sheriff’s Department, the ACLU was joined by the Electronic Frontier Foundation (EFF).

ALPRs are high-speed cameras placed on telephone poles and police cars that collect data on passing cars. According to the ACLU, police have enough data to track the movements of every driver in Los Angeles County on any given day. The Sheriff’s Department and LAPD have amassed a database of a half-billion license plate records.

In 2015, the EFF filed a state Public Records Act request for a week’s worth of scans from the LAPD and the LASD, and along with the ACLU filed a lawsuit.

“The Supreme Court recognized that California’s sweeping public records exemption for police investigations doesn’t cover mass collection of data by police, like the automated scanning of license plates in this case,” the ACLU stated after the ruling. “The court also recognized that mere speculation by police on the harms that might result from releasing information can’t defeat the public’s strong interest in understanding how police surveillance impacts privacy.”

In the ruling, the court lamented privacy concerns over releasing the scans.

“Although we acknowledge that revealing raw ALPR data would be helpful in determining the extent to which ALPR technology threatens privacy, the act of revealing the data would itself jeopardize the privacy of everyone associated with a scanned plate. Given that real parties each conduct more than one million scans per week, this threat to privacy is significant. We therefore conclude that the public interest in preventing such disclosure clearly outweighs the public interest served by disclosure of these records,” the court wrote.