“It’s Public” Is Not the End of the Argument
At every county meeting and in every comment thread, someone says it: if you’re out in public, you have no privacy, so a camera on a public road is fair game. It sounds obvious. It is also not where the Fourth Amendment stops.
It is the single most common defense of Flock and other plate-reader networks, and it sounds like plain common sense: “You’re in public. You have no expectation of privacy. A camera on a public road is fair game.” As a statement of constitutional law, that is incomplete. Yes — police can generally see and photograph a plate visible on a public road. But “it’s public” is not the end of the Fourth Amendment analysis: the Supreme Court and the Fourth Circuit have both recognized a difference between being seen once and technology that can reconstruct your movements over time.
Here is the distinction the “it’s public” line misses. A neighbor who sees your car drive past has caught one moment, in one place, and then it is gone. A plate-reader network does something different in kind: it creates a time-stamped, searchable record of where your car has been — retrievable weeks or months later, copied beyond the agency that captured it, and cross-referenced across thousands of cameras in other towns and other states. One glance is public. A searchable history of where your car has been is not what anyone means by “in public.” And once your plate reads are shared to an agency in another state, North Carolina’s 90-day deletion limit no longer protects them — that copy can be kept indefinitely, out of state, beyond any rule we set here.
That is exactly the line the courts have been drawing, for fifteen years and counting. The principle even has a name — the “whole of a person’s movements” — and here is the doctrine behind it.
The Court struck down warrantless GPS tracking (the majority on trespass grounds); its concurrences — later adopted in Carpenter — recognized a reasonable expectation of privacy in the whole of a person’s movements.
A rolling, aggregated location log is a “detailed, encyclopedic” record of a life — a warrant is required even for movements made in public.
Binding in North Carolina: aerial surveillance of people in public was still a search, because the pooled data revealed the whole of their movements.
Obtaining stored location-history data was a Fourth Amendment search — even the two-hour window at issue, even in public, even when a third party held the data.
Pinpointing a person’s location with a cell-site simulator is a search that requires a warrant.
PENDING — the Fourth Amendment challenge to a Flock ALPR network, now before the appeals court that governs North Carolina.
One honest caveat, because this campaign does not overstate its case. No court has yet held that a plate-reader network is unconstitutional — a trial court upheld Norfolk’s, and in 2026 the Fifth Circuit found periodic plate “hits” were not a search (United States v. Porter). As UNC law professor Jeff Welty puts it, the open question is whether Flock’s scale becomes comprehensive enough to cross the line Carpenter drew. That the line exists is not seriously in doubt. Where Flock falls on it is what the Fourth Circuit will decide in Schmidt v. Norfolk — the case that will bind North Carolina.
So the next time an official waves the concern away with “it’s public,” agree with them — a single look is public. Then ask the real question: is a searchable history of where your car has been for the last month what they meant by ‘public’? The Fourth Amendment says there is a difference. The courts are deciding how big it is. (For the full legal treatment, see our attorney memo, “No Privacy in Public”, and the ALPR cases now in the courts.)
You’re not a suspect. So stop being tracked like one.
It takes one minute. Add your name — then tell the officials who represent you to take the cameras down.