Mayor Matt Mahan helped install an automatic license plate reader on the intersection of King Road and Wilshire Boulevard in San Jose, Calif. on April 23, 2024. (Nollyanne Delacruz/Bay Area News Group)
The government surveils you every time you drive through San Jose, collecting a trove of highly revealing data that police search thousands of times per month without ever seeking a warrant.
It’s an unchecked police power, an end run around judicial oversight and a blatant privacy invasion. It’s also a violation of the California Constitution.
That’s why we at the Electronic Frontier Foundation, with ACLU of Northern California, have sued the city, its police chief and its mayor. Warrantless searches like this violate your right to be free of unreasonable government searches under Article I, Section 13 of the California Constitution and your guarantee of privacy under Article I, Section 1.
Nearly 500 automated license plate reader (ALPR) cameras line the streets of San Jose, quietly capturing and storing images of every driver who passes by. This surveillance network indiscriminately records millions of trips every month, whether people are on their way to work, dropping their kids off at school, seeking health care, going to a place of worship or attending a protest. San Jose stores this data in a massive, central database and holds onto it for a full year — substantially longer than many other cities.
Despite their name, ALPRs record far more than just license plate numbers. San Jose’s fleet of high-speed, computer-controlled cameras automatically log precise locations, timestamps, full photos and even specific vehicle details, including bumper stickers.
San Jose’s ALPR vendor also offers AI-powered features that claim to predict “suspicious” movements and reveal when cars frequently travel to the same places together. Using ALPR location data, San Jose police can easily reconstruct drivers’ movements throughout the city over weeks, months or even a year.
Data from these cameras flows into a central cloud-based, searchable database operated by third-party surveillance company Flock Safety — a firm that’s received negative headlines after its ALPR products were used to assist immigration enforcement, track an abortion seeker and surveil protestors. Flock’s database lets agencies hook into a larger sharing network, and San Jose police have granted hundreds of external law enforcement agencies access to their ALPR database. These outside agencies can also search San Jose’s ALPR data without a warrant.
ALPR supporters insist the surveillance is worth it, that the cameras’ crime-solving magic outweighs any privacy harm. But the numbers tell a different story. San Jose’s cameras captured over 361 million vehicle scans in 2024 alone. Yet only 0.2% of those scans were “hits” matching vehicles on hot lists for stolen cars or wanted suspects.
This means the vast majority of people in San Jose’s sprawling database were under no suspicion whatsoever when their data was collected.
Between June 5, 2024, and June 17, 2025, San Jose police logged more than 261,000 searches of their ALPR database, according to audit logs released in a public records request. This averages out to nearly 700 searches a day.
Factor in searches logged by external law enforcement agencies over the same period, and the search total balloons to nearly 4 million — all without any requirement police get a warrant.
You might ask, “If I’m not doing anything wrong, why should I care?”
But where you drive reveals intimate details about your private life, and you shouldn’t be forced to surrender this privacy, especially without adequate legal safeguards in place. Officers in other cities have abused ALPR data to stalk and harass ex romantic partners and other personal acquaintances. And consider what happens when political winds start blowing in a different direction: Police across the nation have already been using ALPRs to surveil people exercising their constitutional right to protest and to track someone who had an abortion.
There’s one straightforward step to better protect our constitutional rights to privacy: Require police to obtain a warrant before searching the ALPR database.
Real-time alerts for stolen vehicles or wanted suspects could continue unaffected. This simple safeguard would ensure police demonstrate probable cause and receive judicial approval before reconstructing someone’s movements over time.
That’s what we’re suing for on behalf of the Services, Immigrant Rights and Education Network and the Council on American-Islamic Relations of California. The people of San Jose shouldn’t need to sacrifice their privacy just to drive around their city. We must ensure the privacy rights guaranteed by the California Constitution still mean something in the digital age.
Lisa Femia is a staff attorney at the Electronic Frontier Foundation, a nonprofit digital civil liberties group based in San Francisco.
Originally published at Lisa Femia