Two civil liberties groups filed their opening brief with the California Supreme Court late Monday, forcefully arguing that the millions of automated license plate reader records gathered automatically by police throughout the Golden State are not records of investigation.

If the court agrees, such data could be released to anyone as part of the state's public records process. Such a decision would represent a sea change in how automated license plate reader (ALPR, or LPR) data is shared with and scrutinized by the public.

The Electronic Frontier Foundation (EFF) and the American Civil Liberties Union (ACLU) of Southern California originally brought their case against the Los Angeles Police Department and the Los Angeles Sheriff's Department in an attempt to obtain one week's worth of all LPR data. When the agencies refused, the organizations filed suit and lost at both the local and appellate levels.

The lower courts found that the LPR data can be withheld as it does constitute an investigatory file. But the EFF and the ACLU argue:

The Court of Appeal is incorrect: the vast data collection possible with ALPRs is fundamentally different from license plate checks by human officers, and that difference cannot be ignored. Human officers cannot possibly check as many plates per minute as an ALPR system, let alone check the license plate of every car that passes on the streets of Los Angeles. For this reason, an officer manually checking license plates must choose one vehicle to check over others—even if just on the basis of mere suspicion or a hunch. But because ALPRs lack these human limitations, they can collect, check, and store data on every plate that comes into view. ALPRs are untargeted, indiscriminate and comprehensive in a way that human officers can never be. When this Court addressed the investigatory records exemption in Williams and Haynie, it could not have contemplated an application of § 6254(f) that would cover such a vast collection of data.

At present, nearly all state law enforcement agencies have denied the release of such records—whether personalized to one person or generalized to all records of a certain period of time—citing Section 6252(f) of the California Public Records Act . However, some groups like the City of Oakland have decided to release the data.

That provision allows state law enforcement to specifically withhold: "any investigatory or security files compiled by any other state or local police agency." The EFF and the ACLU don't buy this argument.

"That argument is tantamount to saying all drivers in Los Angeles are under criminal investigation at all times," EFF Attorney Jennifer Lynch said in a statement. "The ruling sets a troubling standard that would not just allow these agencies to keep ALPR data from the public but could also allow the police to keep data and footage from other surveillance technologies—from body cameras to drones to face recognition—from ever being scrutinized."