How license-plate reader cameras work
What automated license plate readers (ALPRs) like Flock cameras capture, where they are mounted, how the data is shared, and why it matters, with sources.
Updated 2026-10-12 · data refreshed daily · corrections
What an ALPR is
According to the Electronic Frontier Foundation, automated license plate readers are high-speed, computer-controlled cameras, typically mounted on street poles, streetlights, highway overpasses or mobile trailers, or attached to police cars. They automatically capture every plate that comes into view, along with the location, date and time, and upload it to a central server. EFF notes the photos can include the vehicle and sometimes the driver and passengers.
Fixed vs. mobile cameras
EFF divides ALPRs into categories including fixed cameras (on a pole, a traffic light, a facility entrance or a freeway ramp) and mobile cameras on patrol cars. Fixed cameras generally capture moving vehicles that pass in view; with several along one road, the data can show direction and speed, and with enough cameras police can track a vehicle in real time. Mobile cameras can also capture parked cars, for example sweeping a parking lot (EFF).
Who gets the data
EFF reports that agencies can choose to share their ALPR data with thousands of other agencies, and that in aggregate it can reveal an intimate portrait of a driver's life, including visits to health centers, immigration clinics, gun shops, union halls, protests or places of worship (EFF). Sharing is a major reason communities have reconsidered contracts: NPR reported cancellations over immigration-surveillance concerns, and the Columbus Dispatch reported Columbus removing four ICE-linked agencies from its network.
How many are out there
Nobody publishes an official national inventory. Volunteers map cameras on OpenStreetMap, mostly through DeFlock. As of our snapshot on 2026-10-12, 144,121 license-plate readers were reported in the 50 states and DC; 115,013 of all mapped cameras are tagged with the maker "Flock Safety". These are reported, not verified, and the real number may be higher.
Rules differ by state
National Conference of State Legislatures (NCSL), "Automated License Plate Readers: State Statutes" lists ALPR statutes for some states and none identified for others (updated September 28, 2026). Where laws exist, they cover things like permitted uses, data retention and sharing. See our state-by-state guide.
What you can do
- Look up your street or track your drive.
- Request your local records.
- Show up when your council votes. Our comment builder helps.