Flock Safety sells camera hardware and a cloud platform to individual US cities and police departments on a subscription basis, rather than operating as a single national system the way UK ANPR does. Cameras read licence plates and flag vehicles of interest; because each customer (a city, a department) controls its own camera network and, to varying degrees, who else can query it, ALPR access and retention policy in the US is fragmented rather than standardised.

That fragmentation is also where its most serious documented problems have surfaced. An Illinois state audit found federal immigration authorities had gained access to state plate-read data through an undisclosed arrangement, in apparent tension with a state law restricting data sharing for immigration enforcement, and the state subsequently removed dozens of agencies' access. Separately, Mountain View, California's police department disclosed that federal agencies had accessed its camera data without the city's knowledge, and the city council voted unanimously to end its contract, a specific instance tracked in its own right on the deployment tracker.