Since at least 2014, the Marin County Sheriff’s Office has shared and transferred the sensitive location information of its residents and the people who travel through its boundaries with federal, state, and local agencies across the country, including federal immigration agencies. The Sheriff collects this information using a system of Automated License Plate Reader (“ALPR”) cameras, a mass surveillance technology that automatically records the locations of cars and any visible drivers using cameras mounted on patrol cars, light posts, or other infrastructure. ALPR cameras can automatically scan and record the time-stamped locations of thousands of drivers per day, irrespective of whether those drivers have violated any law.

Using its ALPR system, the Marin County Sheriff’s Office scans tens of thousands of license plates each month, and that sensitive personal information is then stored in a database. The Sheriff permits hundreds of out-of-state agencies and several federal entities, including subcomponents of Immigration and Customs Enforcement (“ICE”) and Customs and Border Protection (“CBP”), to run queries of a license plate against the information the Sheriff has collected. Government agents use this location information to track people’s movements, habits, and associations over time, including where a person lives, worships, protests, and receives medical care. When counties and municipalities like Marin County share and transfer this information to federal immigration agencies like ICE and CBP, it is used to track, detain, and deport immigrants.

In addition to endangering the safety and privacy of local immigrant communities and facilitating location tracking by police, the practice of sharing ALPR information with out-of-state and federal agencies violates two California laws – S.B. 34, which prohibits California entities from sharing ALPR data with non-California entities, and S.B. 54, which limits the use of local resources to assist federal immigration enforcement.

On October 14, 2021, three community activists in Northern California, Cesar S. Lagleva Jr., Lisa Bennett, and Tara Evans, sued the Marin County Sheriff for illegally sharing millions of local drivers’ license plates and location data through its ALPR system. The Plaintiffs seek to compel the Marin County Sheriff to comply with state law by ending the sharing and transferring of ALPR information with out-of-state and federal entities and with agencies the Sheriff knows to provide ALPR information to out-of-state and federal entities, as well as prevent the illegal expenditure of county funds on these practices.

This lawsuit is the first of its kind to challenge the sharing of private information collected by ALPR mass surveillance.

Press Release:


Vasudha Talla & Matthew Cagle, ACLU of Northern California; Mohammad Tajsar, ACLU of Southern California; Mitra Ebadolahi & Emily Child, ACLU of San Diego and Imperial Counties; Saira Hussain & Adam Schwartz, Electronic Frontier Foundation; Michael Risher

Date filed

October 14, 2021


Marin County Superior Court


Stephen P. Freccero



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