The Problem

Warrantless mass surveillance turns ordinary public life into a searchable government record — without suspicion, without a warrant, and mostly without anyone noticing.

Surveillance got cheap. The Constitution didn’t change.

For most of American history, following one person took effort: officers, time, and money. That practical cost was itself a safeguard — government watched people it had reason to watch. Modern surveillance technology removes the cost. It is now inexpensive to observe everyone, retain the records indefinitely, and search them at will.

The fact that a surveillance capability is inexpensive, automated, scalable, or useful does not erase limits on government power. Constitutional protections should become more important — not less — as technology makes it possible to observe more people, retain more information, combine more datasets, and reconstruct more of a person’s life. A constitutional system should not depend on every person with database access behaving perfectly forever.

The current instance: automated license plate readers

Automated license plate readers (ALPRs) are the clearest example of the broader problem, because the mechanism is easy to follow:

Cameras continuously capture vehicles that are not suspected of any crime.
Plate observations are stored and aggregated.
Networked systems allow retrospective searches across large geographic areas.
The resulting data can reveal patterns of movement, relationships, homes, workplaces, religious attendance, medical visits, political activity, and other sensitive associations.
Abuse has already been publicly documented.

The documented abuse

reported incidents in which law-enforcement personnel allegedly used ALPR systems to stalk romantic interests or people they were personally pursuing, identified by the Institute for Justice^[1]

These are identified cases — not a census of every ALPR-using jurisdiction.
Compiled through an ongoing review of media reports and public records.
The incidents span September 2021 through July 2026.
They occurred across 29 jurisdictions in 12 states.
IJ explicitly describes the list as “almost certainly an undercount.”
Most reportedly surfaced after victims complained — not through proactive internal detection.

Thirty is not the total number of ALPR stalking cases. It is only the number one civil-liberties review could find publicly — and the reviewers call it “almost certainly an undercount.”

The detection pattern is the point. If most known abuse surfaced only because a victim noticed and complained, internal audits are not catching misuse on their own — and the documented cases are a floor, not a ceiling.

“Your phone already tracks you.”

The common pushback

“Your smartphone and your smart speaker already track you. Why does one more camera matter?”

Your smartphone is a choice. Government surveillance isn’t. The existence of voluntary consumer technology does not constitute consent to government surveillance.

Consumer devices and services are generally optional to varying degrees; public roads and ordinary participation in community life are not meaningful surveillance opt-ins.
People can make different consumer choices, disable permissions, use privacy-preserving configurations, or avoid particular devices entirely. There is no setting that removes your car from a government camera network.
Even in the private sector, Unsurveilled supports meaningful affirmative consent — not opaque privacy policies or manipulative defaults.
A person choosing one technology company’s product does not grant unrelated government agencies permission to create their own searchable history of that person’s life.

The constitutional standard

The central argument is that prolonged, networked, searchable location surveillance raises serious Fourth Amendment^[2] concerns, particularly when the government can reconstruct a person’s movements without individualized suspicion or a warrant.

Warrantless mass ALPR surveillance violates the principles and protections of the Fourth Amendment.

The U.S. Supreme Court has not categorically ruled on ALPR networks, and we will not pretend otherwise. But the trajectory of its location-privacy decisions matters: in United States v. Jones^[3] the Court held that attaching a GPS tracker to a vehicle is a Fourth Amendment search, and in Carpenter v. United States^[4] it held that the government generally needs a warrant to obtain historical cell-site location records that chronicle a person’s movements. The concern in both cases — retrospective, effortless reconstruction of where a person has been — is precisely what networked ALPR databases are built to do.

Arizona adds an independent foundation. Article II, §8 of the Arizona Constitution^[5] provides that no person “shall be disturbed in his private affairs, or his home invaded, without authority of law” — state-level privacy language that Unsurveilled Arizona is researching as a basis for reform. See the Arizona chapter for that work.

The full picture — including the only state supreme court decision squarely about license plate readers, the 2026 Supreme Court location-privacy ruling, and the authority that cuts against us — is on The Law. If you are going to argue this in public, read the hedging there first.

The test any surveillance power should pass

Would the power still be acceptable if the political party in power, the police administration, the technology vendor, and the surveillance target all changed tomorrow? A durable constitutional system relies on enforceable limits — not on permanent confidence in whoever currently holds access.

Every factual claim on this page is documented in the sources library. If we have something wrong, tell us — we correct mistakes publicly.