License Plate Reader Searches Should Require a Warrant

Either it needs a warrant or it’s fully open and people can start creating websites showing the movements of local politicians.

This middle ground that municipalities try to carve out where it’s fully open to police without a warrant but not subject to FOIL laws doesn’t appear tenable for much longer.

There’s been too many cases of police officers stalking exes, poking around the data for fun and such so it’s clear police cannot be trusted with the data without better court oversight.

It’s certainly a very powerful investigative tool, but needs solid 4th amendment protections. The Supreme Court’s recent ruling on geofence searches of cell phone records is a good indication on where the Supreme Court’s head is at on this sort of thing, where they said no you can’t just do blanket data dumps like that without a warrant.

It frustrates me when people call them license plate readers. I guess you need to call them something, but they are general-purpose internet connected cameras. They will do whatever their firmware tells them to do, and could be reprogrammed at any time by anyone with access. No one expected doorbell cameras to join a mass surveillance network, but later the manufacturers added that feature. Why do we treat these cameras like they can do only one thing?

This is a hole in the Constitution that would be better patched, at least with statute, better with an amendment. The fourth amendment says

  The right of the people to be secure in their persons, houses, papers, and effects...

Attempts to interpret the Constitution otherwise are, IMHO, attempts at good policy, but unstable as law. So we should fix it either by giving people property rights to that data (so that they can destroy or change it without permission) or to explicitly require warrants for access to PII owned by third parties.

Monetization of public data for private profit is the heart of my qualms.

Why should it be possible for my bits be scooped up and sold for profit against my will.

Here's a case study of what happens when this information is public (it's linked as the "data-driven" series). This information should not exist unless the plate is flagged and the reason for that is sufficient to obtain a warrant. https://www.eff.org/deeplinks/2026/04/open-records-laws-reve...

Good article. It's a sober look at where we are at.

We lost a lot of strong privacy rights we had with landlines when we shifted to cell phones.

We're actually slowly creeping into pre-crime territory. You could have AI searching for possible pre-crime candidates based on unknown identity in the area, disparate pattern to usually movements, etc.

I don't like the article's tone of inevitability:

> I think cameras in all public spaces are going to happen. Imagine Ring comes out with a nicer camera system for homeowners....

Indiscriminately filming people in public places is illegal some places, e.g. Germany. Allowing the creation of large networks of cameras surveilling public places is a choice.

A license plate is already publicly displayed information (and is in most jurisdictions not private property), and you're operating in a public space.

I know it's unpopular but I went from not supporting these sorts of systems to embracing them after seeing the positive effects in China.

For crimes that depend on anonymity, theft, assault, hit-and-runs, vandalism, illegal parking, etc., surveillance changes the calculation because the offender expects a higher or even a near certain chance of being identified/caught in China. I think this is a good thing. I also see no issue with someone breaking the law and receiving a ticket almost immediately.

With all systems, it comes down to the design. What sort of oversight is there, how long is footage stored, can it be used for specific crimes or expanded later, and are there mechanisms to correct false identification.

Done right, these systems work well. I would be happy to live in a society where street crime is rare enough that I can leave personal property anywhere, like a bike, without constantly worrying about theft. I think many fears about these systems come from dystopian science fiction and assume the worst possible implementation, rather than recognizing that technology can be designed with strong safeguards.

Hotlists imply that actual search takes place the moment you pass one, so really, the illegal search happens before. Even if warrants were required to manually search.

Yeaaah for seeing Andy on HN. His stuff is always excellent.

I am for having it be completely open to the public, or require a warrant. The police should not have special privileges of information lifted directly from the public. Privacy cuts both ways.

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Why is this relevant to Hacker news?