PUBLIC - This article does not require an IPVM subscription. Feel free to share.
Online, Flock draws far more critics than defenders. But among those who do, the most common argument is a familiar one: there is no expectation of privacy in public, and license plates are visible to anyone on the road, so what's the problem? It is a reasonable instinct. It is also an oversimplification, and not what courts are being asked to decide.
Executive Summary
The "no expectation of privacy in public" defense is understandable and not entirely false in isolation. But it is the wrong frame for the fight that is actually happening, and every litigant in this debate, including Flock, has recognized that. The real contest is the dragnet threshold: whether Flock's national network aggregates enough public data to track the "whole of a person's movements" and constitute a search under Carpenter v. United States. Flock's own CLO has conceded that the day warrants will be required is coming. The debate is about density and timing, not public visibility.
The Argument Is Understandable
The people making this argument start from a reasonable place. A Hacker News commenter, responding to IPVM's report on police chiefs using Flock to stalk women, put it this way:
There's nothing against the law for a police officer to stand at an intersection writing down all passing car's license plates with a pen and paper. Flock is the same thing, just much more cost efficient.
Todd Welch, a Herald columnist, wrote in March 2026:
Courts have long recognized that individuals have a reduced expectation of privacy when traveling on public roads. A camera capturing an image of a license plate that is openly displayed on a vehicle is not searching for someone's private life. It is recording what anyone standing on the same street could already observe.
You have no expectation of privacy while traveling on a public road. Your license plate is not private information.
These are established positions, grounded in law. The plain-view doctrine is settled, including for license plates. A single camera at a single intersection photographing a plate on a public road is legally defensible, and courts have agreed on this for decades. IPVM agrees: one camera, one intersection, one moment is solid legal ground.
It Breaks Down at National Network Scale
However, Flock markets itself as the "NATIONAL LPR NETWORK", with "coast-to-coast reach" and the ability to "track suspects across counties and state lines."
Approximately 90,000 cameras. Twenty billion plate reads per month. Every read is stored, searchable, and shareable across thousands of agencies. That is a fundamentally different instrument than a cop with a notepad.
The Supreme Court directly addressed this principle in Carpenter v. United States (2018): "A person does not surrender all Fourth Amendment protection by venturing into the public sphere." The aggregation of individually public moments can itself constitute a constitutionally protected category. That aggregation principle is the framework every court hearing a Flock case is working within.
Three plaintiffs in the Institute for Justice's federal lawsuit against San Jose each stated that if any individual person tracked their movements the way Flock does, they would call it stalking.
Courts have ruled for Flock, but primarily based on density. A Norfolk federal judge found in his ruling that "pronounced gaps" in the city's 172-camera network fell short of dragnet territory. That ruling is now on appeal to the Fourth Circuit. A Kansas federal court ruling in April 2025 similarly sided with Flock but added: "The fact that the Flock System does not presently violate an expectation of privacy does not foreclose the potential for Flock to one day rise to the level of dragnet search." Significantly, both rulings carry that hedge.
Flock Knows This
Flock's white paper, published in November 2025 and citing 30 court decisions, confines its defense to point-in-time observations, vehicles and plates rather than people, 30-day deletion, and current camera density being insufficient to constitute a dragnet.
Flock states:
The constitutional concern arises when technology stitches together a comprehensive portrait of someone's movements over time that can reveal intimate and sensitive details. Fixed, point-in-time roadway observations occupy the other side of that line.
Flock is not arguing that surveilling people in public is categorically fine. It is arguing that its system does not yet cross the line into a comprehensive portrait — a Carpenter argument, not a "no privacy in public" argument.
CLO Dan Haley's public statements follow identical logic. His defense centers on discreteness and current density, and on the vehicles-not-people distinction — a framing IPVM has analyzed in depth. When Haley cited the Norfolk ruling as a legal victory, he shifted to density as the operative constitutional standard. Density is central to Haley's argument because the plain-view framing alone is insufficient under Carpenter, and Haley knows it.
Similarly, CCO Josh Thomas, in a June 2026 interview, qualified every denial that Flock tracks people with the phrase "the whole of your movements," the Supreme Court's own language from Carpenter.
As IPVM documented, Thomas invoked the Carpenter threshold as a denial. Someone who believed "no privacy in public" settled the matter would have no need for that qualifier.
The most candid statement came from Haley after the Norfolk ruling, in remarks IPVM covered. He said directly:
There will come a time where this technology could get ubiquitous enough and powerful enough that there needs to be a warrant requirement... That day in the future is out there. When it comes, we'll build tools to enable that. It's just not yet.
Flock's own CLO is defending current density while conceding the endpoint. The admission carries more weight given the growth trajectory: Flock has raised over $750 million at a $8.4 billion valuation. Its investor pitch depends on more cameras and denser networks, running directly toward the threshold its own CLO has already acknowledged.
The Right Question
Nobody sophisticated in this debate is arguing about whether photographing a license plate on a public road is legal. That question has been settled for decades and is agreed on by all sides. The question in federal courts in Virginia, Kansas, and California is whether Flock's national network constitutes a dragnet. "Does not presently" is a ruling with an undefined expiration date. The real debate is about when Flock will cross it.