SCOTUS gets into it in their opinions on Chartrie, you should check it out.

They wrestle with the balance there of 4th amendment protections and mass surveillance. It's evolving and generally courts are moving to not allowing mass surveillance -or less so than they have allowed in. Courts have been split on it, and someone already pointed it out that SCOTUS will eventually come up with tests for it.

There were some really interesting parts of those Chatrie opinions that really will test the idea that someone in public gives up their right to any privacy - the fundamental underpinning of why governments can currently point cameras at public places and dont need a warrant to search that video.

Chatrie protected the aggregated viewpoint versus any single public moment - And SCOTUS said the aggregated viewpoint (mass search of location data with no specific person(s)) is not allowed under the 4th amendment. A very interesting precedent.

Gorsuch had an interesting take in that he argued that in Chatrie the location data was Chatrie's personal property and therefore protected from illegal searches from government.

There are a lot of similarities to how ALPRs work, and key differences. Mostly Chatrie deals with a private firms data collection of locations - google vs ALPRs are generally on publicly owned property and recoding things in public.

Still, many justices opened the door to the idea that the government can't mass surveil citizens. We'll have to wait and see how it all plays out.

I am very much of the opinion the government should need a warrant to search through ALPR data (and video for that matter). So, I am hopeful that the tenets of Chatrie extend to ALPRs, video, etc.

Edit: Gorsuch argues that the data is personal and not the government's data - this is what prevents the government from searching for it without a warrant. He did not get into why a body cam or something like that is different.

Sometimes the law is vibes, SCOTUS will probably create a set of tests where lower courts will have to look at how many points it hits and decide whether it's over the line on a case by case basis.

I don't know what the philosophical answer is, but the real answer is that we don't, the supreme Court does.

The number of cameras matters much less than what those cameras are being used for. If police body cam footage was being indiscriminately scanned for any and all license plate data and all of that data was being fed into a national database which was being routinely accessed and abused that would also be problem. As far as I know, that isn't the case.

Given that in the majority of places police are typically busy doing things like writing speeding tickets and going on calls that leaves a lot less time for them to sit still for an 8 hour shift and record every single plate they can see 24/7/365. Those 5 cameras would represent 15 to 20 officers which is a huge taskforce no matter how large the department.