Automated license plate readers (ALPRs) build a searchable map of everywhere a driver goes, fed into databases that police, ICE, and private vendors can query after the fact. Networked across a city, ALPRs are purpose-built to track everyone regardless of suspicion. ALPRs are not a surveillance tool that can be made safe with the right policy or feature update—they are irredeemably harmful.

EFF’s position is that ALPR mass surveillance—the indiscriminate, continuous collection and retention of location data on every driver, regardless of suspicion—should not exist. Because it nonetheless does, EFF also urges courts and state legislatures to impose strict, enforceable restrictions, such as warrant requirements and deletion deadlines.

EFF’s position is that ALPR mass surveillance—the indiscriminate, continuous collection and retention of location data on every driver, regardless of suspicion—should not exist. Because it nonetheless does, EFF also urges courts and state legislatures to impose strict, enforceable restrictions, such as warrant requirements and deletion deadlines. EFF applies every tool available to eliminate ALPR surveillance and the harm it enacts.

The Case Against ALPRs

A note about scope: This post addresses ALPR mass surveillance. It does not address the wider universe of automated traffic enforcement (ATE) such as conventional red light and speed cameras that solely ticket a specific violation, without retaining or networking data on uninvolved drivers. But lawmakers and purchasers should guard against efforts by vendors to piggyback on ATE contracts to market ALPR mass surveillance systems.

ALPRs are frequently marketed as a narrow tool for specific purposes, such as recovering stolen vehicles. But in practice, these sensors sweep up data on every driver who passes a camera, and store it in searchable databases. That indiscriminate collection and retention is precisely why ALPR-fed surveillance systems can be easily weaponized against immigrants, political dissidents, and other targeted communities as ICE and other federal agencies escalate their assault on civil liberties. There is no configuration of an ALPR network that eliminates this risk, because the risk is the mass surveillance itself, not a misuse of it.

Of course, ALPRs cause other predictable harms. Innocent drivers are recurringly arrested and menaced by police because of ALPR errors. Officers regularly abuse ALPR systems to stalk past and potential romantic partners. Creating any database of personal information—including ALPR surveillance databases—inherently creates risk of data theft and subsequent harm to data subjects. And ALPR surveillance of protests and targeting of activists chill participation in First Amendment-protected dissent. But even if these downstream harms could all be prevented (and they likely can’t), ALPRs would remain an intolerable form of mass surveillance.

Fighting on Every Front to Eliminate ALPR Surveillance

At the city level, EFF works with community members and decision makers to outright refuse ALPR purchasing. ALPRs are not inevitable. The same decision mechanisms used to facilitate runaway surveillance purchasing in U.S. localities can be turned against these systems to dismantle them.

EFF also pushes state legislatures to establish strict state-level limits on ALPR surveillance, such as data-deletion rules and use restrictions. Building such constraints into statute can mitigate the harms of existing ALPR systems.

In courts across the country, EFF files amicus briefs arguing that warrantless police searches of ALPR databases violate the Fourth Amendment. In California state court, EFF and the ACLU of Northern California are suing on behalf of two community groups, SIREN and CAIR-CA, arguing that the San Jose Police Department’s practice of letting officers search stored plate data—to the tune of over 100,000 times a year—without a warrant violates the California Constitution. We’ve also sued to block California law enforcement from sharing ALPR data with federal and out-of-state agencies, in violation of a California statute.

A big part of EFF’s work is exposing the harms of ALPR surveillance. Our investigative team tirelessly collects information about how law enforcement uses ALPRs with public records requests, sues to enforce such requests, and publishes reports about them. We’ve also successfully lobbied for a State Auditor investigation of law enforcement’s use of ALPRs.

Coordinated Action Against Mass Surveillance

EFF practices integrated advocacy because all of these tools work best together. City refusals, statehouse restrictions, impact litigation, and investigative activism are different levers EFF pulls toward the same end: eliminating ALPR surveillance, and building the durable public power needed to keep it off our streets. A council vote against a Flock contract and a warrant argument in Santa Clara County Superior Court are both, at their core, the same fight: rejecting mass surveillance infrastructure outright, and using every venue available to eliminate its harmful presence and consequences.