SAN JOSE — A coalition of high-profile civil-liberties groups led by the Electronic Frontier Foundation and ACLU is suing San Jose over what it characterizes as millions of warrantless searches of automated license plate reader data, which it says has put the city in an unprecedented state of surveillance with no meaningful gatekeeping.
The lawsuit, filed Tuesday in Santa Clara County Superior Court, claims that local authorities as well as outside law enforcement are violating the California Constitution by continuously combing, without a search warrant, the hundreds of millions of data points captured annually by the roughly 500 plate-reading cameras installed throughout the city.
For the plaintiffs — who also include the immigrant-rights organization SIREN and the Bay Area chapter of the Council on American–Islamic Relations — that amounts to virtually unchecked “retrospective” monitoring of people’s movements in Northern California’s largest city, and the litigation is aimed at reining it in.
“This practice violates the California Constitution’s ban on unreasonable searches … so we’re asking the court to declare that these warrantless searches are unconstitutional and order the defendants to stop this practice,” EFF staff attorney Jennifer Pinsof told this news organization. “This would be an important limit on ALPRs because without a warrant, there is an unchecked police power to scrutinize the movements of San Jose’s residents and visitors as they travel from home to work, drop off their children at school, or park at a house of worship, a doctor’s office, or a protest.”
The lawsuit names as defendants the city of San Jose, Mayor Matt Mahan and Police Chief Paul Joseph. The San Jose Police Department declined comment, citing the pending litigation.
Mahan and other San Jose leaders have spent the past two years touting the benefits of the plate readers, contracted through Flock Systems. Early pilot programs were introduced as a way to curb deadly vehicle-pedestrian collisions at some of the city’s busiest intersections. And as the city commissioned more, officials and the police department have credited the cameras as key contributors to arrests in high-level crimes including homicides and organized retail thefts: SJPD has prominently cited ALPR data in at least a half-dozen news releases from the past year.
“While I can’t comment on pending litigation, I can tell you that pursuant to state law we have built in robust data privacy and security measures throughout our ALPR system, including regular deletion of collected data that is not being actively used in an investigation,” Mahan said in a statement Tuesday. “While we take seriously our responsibility for data privacy and security, we can’t let fear of new tools get in the way of the safety of our families, especially given that this system is a big part of the reason we’ve solved 100% of homicides over the past three years.”
The technology has drawn its share of critics, particularly in the civil-liberties sphere. Earlier this year, the watchdog group Oakland Privacy cited a database of ALPR access by Southern California police agencies showing that they were illegally sharing data with U.S. Immigrations and Customs Enforcement and Border Patrol agents.
But also, on the same day of the lawsuit filing, the Oakland chapter of the NAACP called for Oakland to bolster its commitment to ALPR cameras as a vital crime-fighting measure.
Without a warrant requirement, SIREN Executive Director Huy Tran forewarns scenarios where authorities — especially given the external access — could freely track a person traveling to a reproductive clinic or an immigration law firm.
“The right to privacy is one of the strongest protections that our immigrant communities have in the face of these acts of violence and terrorism from the federal government,” Tran said in a statement. “This case does not raise the question of whether these cameras should be used. What we need to guard against is a surveillance state, particularly when we have seen other cities or counties violate laws that prohibit collaborating with ICE. We can protect the privacy rights of our residents with one simple rule: Access to the data should only happen once approved under a judicial warrant.”
Tuesday’s lawsuit draws on a search of a public-facing transparency portal hosted by Flock that offers aggregate figures on how often license plate data recorded in San Jose is searched by local police.
The public data shows that in 2024, ALPR cameras in San Jose made more than 361 million plate scans, and that just over 923,000 of those scans corresponded with hits on vehicles that were being sought, or 0.2 percent. A recent slice of data, from this past October, found that 6.4% of 2.6 million scanned vehicles returned links to crimes or investigations.
The plaintiffs make a point of distinguishing these instances from the vast majority of vehicles that are recorded but not the subject of any criminal suspicion. Even so, the public data posted by Flock — and summarized in the filing — shows how routine SJPD searches the database, largely for non-exigent reasons, which is a pillar of the lawsuit.
In a one-year period ending this past June, SJPD conducted over 261,000 searches of the database, equating to 692 searches a day. But when accounting for other state law enforcement agencies that also have access, that search total jumps to nearly 4 million searches in the same period, or 10,864 a day.
The plaintiffs argue that San Jose’s one-year retention period for ALPR data, combined with officers’ mostly unrestricted access to the database, means that people who drive a car in San Jose can be extensively tracked without any clear limits. The lawsuit adds that the only way to opt out of this data collection is not to drive at all.
“San Jose has quietly built one of the most sweeping license plate surveillance systems in the state, funded by the very residents whose lives it tracks,” Zahra Billoo, executive director of CAIR-San Francisco Bay Area, said in a statement. “The California Constitution promises real privacy protections, and this lawsuit is about making sure those promises still mean something for everyone who drives through San Jose.”
The feasibility of officers securing a warrant every time they search past ALPR data remains to be seen, but it would almost certainly be cumbersome, and Pinsof said that friction is the point. She added that while the litigation filed Tuesday focuses on San Jose, she hopes that broader law enforcement takes notice.
“Unfortunately, in the golden age of surveillance we’re currently living in, this technology has moved faster than legal protections of our privacy,” she said. “Now we need to take back our privacy and other freedoms, by placing critical limits on how police use ALPR data.”
