The Marin County Sheriff’s Office is the latest California law enforcement agency to get caught sharing automated license plate reader (ALPR) data from their Flock Safety system with out-of-state and federal agencies. EFF and the ACLU of Northern California are calling them out for this direct violation of California law, which has put every driver in the county at risk and is especially dangerous for immigrants, abortion seekers, and other targets of the federal government.

Today, we sent the Marin County Sheriff’s Office (MCSO) a demand letter and request for records under the California Public Records Act following the Point Reyes Light’s recent report that MCSO provided non-California agencies access to its ALPR database. This directly violates California law and the terms of the 2022 Settlement Agreement in our case Lagleva v. Marin County Sheriff.

ALPRs are cameras that capture images of vehicles and upload their location to a searchable, shareable database. They are a mass surveillance technology that collects data indiscriminately on every vehicle on the road.

Sharing ALPR data with out-of-state or federal agencies—for any reason—violates California law (SB 34). If this data is shared for the purpose of assisting with immigration enforcement, agencies violate an additional California law (SB 54).  

But network audit logs obtained by Point Reyes Light show that during the final months of 2024, Marin County Sheriff’s Office shared ALPR data with multiple out-of-state and federal agencies, including 254,131 times in November 2024 alone. Many of these searches were conducted by law enforcement in states that impose severe restrictions on reproductive care and have a history of assisting ICE, including Alabama, Indiana, Kentucky, Florida, and Texas.

This sharing violated state law and “exposed sensitive driver location information to misuse by the federal government and by states that lack California’s robust privacy protections,” the letter explains.

This is not the first time MCSO has shared Marin County ALPR information with federal and out-of-state agencies in violation of California law.

Back in 2021, on behalf of community activists, EFF and ACLU sued the Marin County Sheriff for illegally sharing millions of local drivers’ license plate numbers and location data with hundreds of federal and out-of-state agencies, including ICE and Border Patrol.

The parties eventually reached a settlement, under which the Sheriff agreed to stop sharing license plate and location information with agencies outside of California to comply with state laws SB 34 and SB 54.

“MCSO’s November 2024 audit report shows that your office has violated not only SB 34, but the terms of the Lagleva Settlement Agreement as well,” the letter explains.

EFF and ACLU are urging MCSO to launch a thorough audit of its ALPR database, institute new protocols for compliance, and assess penalties for any employee found to be sharing ALPR information out of state.

“While your office claims that it took deliberate steps to disable nationwide data-access capabilities and ensure your system operated within strict privacy safeguards, you have not explained how outside agencies nonetheless obtained access, how you plan to prevent future violations of SB 34 and the Lagleva Settlement Agreement, or why you did not take steps to inform the public and the Marin County Inspector General once you learned about the breach,” the letter explains.

As we’ve demonstrated over and over again, many California agencies continue to ignore these laws, exposing sensitive location information to misuse and putting entire communities at risk. As federal agencies continue to carry out violent ICE raids, and many states enforce harsh, draconian restrictions on abortion, ALPR technology is already being used to target and surveil immigrants and abortion seekers. These incidents have made it clear that having ALPR programs are incompatible with the protection of residents. California agencies, including Marin County Sheriff’s Office, have an obligation to protect the rights of Californians, even when those rights are not recognized by other states or the federal government. 

See the full letter here: https://www.eff.org/document/20261001-letter-aclu-norcal-and-eff-marin-sheriff