Privacy and Technology

The ACLU of Northern California defends the right to privacy guaranteed by the California Constitution and fights for social justice in the digital age. We work to stop dangerous government surveillance, eliminate bias in artificial intelligence and other emerging technologies, and restrict the online collection and use of our personal data.

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The Latest

Press Release
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Canadian Trump Critic Sues to Stop Google from Sharing Personal Information with Department of Homeland Security

DHS unlawfully attempted to obtain personal information, including location and physical movements, of Canadian citizen
Press Release
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ACLU Sues San Francisco Landlords over AI-Powered Surveillance in Tenants' Homes

Issue Areas: Privacy and Technology
Press Release
Graphic of Automatic license plate readers

Lawsuit Challenges San Jose’s Warrantless ALPR Mass Surveillance

EFF and the ACLU of Northern California Sue on Behalf of Local Nonprofits
News & Commentary
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Mass Surveillance in the Trump Era

The Trump administration is weaponizing technology to build a mass-surveillance state.
Court Case
May 04, 2026

John Doe v. Markwayne Mullin

The ACLU Foundation of Northern California and the ACLU of the District of Columbia sued the U.S. Department of Homeland Security (DHS) over its unlawful attempt to obtain from Google the personal and location information of a Canadian citizen who has posted content critical of the Trump administration online. This case is among a large number of instances of social media critics who have been targeted by DHS. Since the start of the second Trump administration, social media platforms have received hundreds of similar government demands for information designed to chill speech the government doesn’t like. Our lawsuit asks the court to rule that DHS is exceeding its legal authority by demanding vast swaths of personal information about the plaintiff, including his name, where he lives, extensive information about his physical movements, and detailed records about the websites he visits and the people he communicates with online. On his social media accounts, the plaintiff, John Doe, who uses a pseudonym to protect his privacy and family, regularly posts strongly worded criticisms of President Trump and his policies. In February, DHS issued an administrative demand to Google to release his personal information shortly after he posted online criticism of the killings of Renee Good and Alex Pretti by federal agents in Minneapolis. The attempt to force Google to turn over information about Mr. Doe far exceeds DHS’s legal authority, which the agency issued without any involvement from a court, citing a customs enforcement law. Mr. Doe, a Canadian citizen who resides in Canada, has not entered the U.S. since 2015. The ACLU of Northern California, the ACLU of Pennsylvania, and the ACLU national organization have filed three other cases challenging similar abuses, but DHS withdrew those subpoenas before a judge could rule on their legality. This lawsuit, filed in the Northern District of California, goes a step further than previous challenges. It asks the court to not only invalidate this summons, but also make clear that the government may not use its customs enforcement authority to attempt to identify and intimidate its critics.
Court Case
Jan 20, 2026

SIREN, et al. v. City of San Jose, et al.

The ACLU of Northern California and the Electronic Frontier Foundation filed suit in Santa Clara County Superior Court against the City of San Jose and others to challenge San Jose police officers’ practice of searching for location information collected by automated license plate readers (ALPRs) without first getting a warrant.
Court Case
Jan 21, 2026

San Francisco Tenants Union, et al. v. Smart Rent, et al.

The ACLU’s lawsuit in San Francisco Superior Court seeks to protects tenants' privacy rights from landlords who force renters to allow AI-powered surveillance technology in their homes. In multiple residential buildings across San Francisco, landlords have forced tenants to accept so-called “smart home” systems that monitor their comings and goings and other behavior. They're using tenants’ personal information to track them, potentially even profiling their behavior with AI tools built specially for landlords.
Court Case
Dec 09, 2025

J. Doe v. United States Department of Homeland Security

We filed a motion in federal court to prevent Meta from complying with the Department of Homeland Security’s demand that the tech giant turn over the name, email address, and phone number associated with an Instagram account that reposted a video naming a Border Patrol agent. We argue that the government’s administrative subpoena violated First Amendment protections for anonymous political speech.