ALPR Cameras: What They Are, Where They Are, and What They Know
You drove to work today. Somewhere between your driveway and your parking spot, your license plate was read by an automatic camera, matched against a database, and logged with a timestamp and GPS coordinates.
This probably happened multiple times. On average, a license plate in a US metro area is scanned 60-70 times per month.
What are ALPR cameras?
Automatic License Plate Readers are cameras with built-in optical character recognition. They photograph every passing vehicle, extract the plate number, and log it with timestamp, GPS coordinates, vehicle make, model, color, and sometimes bumper stickers and distinguishing marks.
The largest operator in the US is Flock Safety, with 80,000+ cameras across 49 states, scanning approximately 20 billion plates per month.
Where are they?
Everywhere you’d expect a camera, and many places you wouldn’t:
- Police patrol vehicles (mobile ALPR)
- Highway overpasses and bridge tolling points
- Intersection poles alongside traffic lights
- Parking lot entrances (shopping malls, airports, hospitals)
- Residential neighborhood entrances
- Repossession company vehicles
- Private security patrols
Sentinel maps 8,600+ ALPR cameras across 99 countries. See them on the map.
What do they know about you?
A single ALPR scan tells an operator:
- Where you were
- When you were there
- What vehicle you were driving
- Which direction you were heading
Aggregated over time, ALPR data creates a comprehensive pattern of your life: where you work, where you live, where you shop, who you visit, what doctor you see, where you worship, and what time you leave home each morning.
This data is retained for years. Flock Safety retains data for 30 days by default, but many police departments extend this to 1-5 years. Some agencies retain ALPR data indefinitely.
Who has access?
This is where it gets complicated.
Flock Safety operates a data-sharing network between law enforcement agencies. A camera operated by one police department can share its data with hundreds of other departments through interconnection agreements.
ICE (Immigration and Customs Enforcement) has accessed ALPR data through local police “side doors” at least 466 times between 2017-2019 (according to ACLU FOIA documents), despite not operating cameras directly.
Insurance companies, repo firms, and private investigators can also purchase access to commercial ALPR databases.
Can you opt out?
No. There is no opt-out mechanism for ALPR scanning. You cannot request that your plate be excluded from the system. The cameras photograph every vehicle that passes, regardless of whether you’re suspected of anything.
Some jurisdictions have proposed ALPR regulation:
- Vermont prohibits government ALPR use entirely
- Several states limit retention periods
- The EU’s GDPR has been tested but not definitively applied to ALPR
In practice, the technology operates with minimal oversight in most jurisdictions.
What you can do
Awareness is the first step. Open Sentinel and filter for ALPR cameras to see how many are on your daily commute. Toggle the ALPR filter and zoom into your city.
The cameras don’t go away. But now you can see them.