Your license plate was photographed today

Automated license plate readers, or ALPRs, are cameras that photograph every vehicle that passes them. Each capture logs your plate, the time, and the location, and stores it in the vendor's database. The largest vendor, Flock Safety, sells them to police departments, homeowners associations, and businesses across the country. If you drive, your movements are in somebody's ALPR database.

What the cameras do

The system works in two modes. A hotlist holds plates police are actively looking for: stolen cars, wanted suspects, missing children. When one passes a camera, officers get an alert. That is targeted police work, and it is the mode the sales pitch leads with.

The cameras also photograph and store every other car, whether or not anyone is looking for it. Those records sit in the database for weeks, where an officer can search them later. Minnesota law caps the storage at 60 days. St. Louis Park, the city in our deepest ALPR investigation, holds its data for 30.

Who can search your movements

By default, Flock makes every customer discoverable to every other one and turns data sharing on unless someone switches it off. An independent audit of a Minnesota task force laid this out, and raised a second problem: the system keeps no record of who downloads data, so there is no way to know what leaves it.

The reach surprises the cities themselves. Capitola, California runs ten cameras; 25 outside agencies asked to search them in ten weeks. In St. Louis Park, Minnesota, outside agencies ran 2,637 searches tied to immigration enforcement against the city's 16 cameras, about 95 percent of them from out of state. A Texas deputy searched for a woman who had an abortion.

When cities push back

Flock knows the records bother people. When public records requests started arriving in Capitola, Flock sent the police department a playbook for narrowing them. The same city shows the other path: Capitola's police chief rewrote Flock's data clause and is demanding more amendments at renewal. The defaults belong to the vendor. The settings belong to the city.

Where to go next

If you live in Minnesota, FlockFeed logs changes to Flock transparency portals statewide, and ALPR Audit Watch reads the audits state law requires. For the full story of one city's cameras, read the St. Louis Park investigation. Anywhere else, EFF's Atlas of Surveillance maps which agencies near you run ALPRs.