Yes. I worked for a city and was tasked with occasionally reading emails that had been reported. I got to read some interesting ones, but the one I’m talking about: The auto-theft detective was informing patrol officers about the setting up of the device I described. It would send an email when a vehicle’s license plate was scanned and was returned with a STOLEN result. The majority of the email was about how the officers should not mention the device and only say that they had received a tip about a stolen vehicle.

We aren’t talking about the permanent sorts of signs, like those described by @reversalhatchery@beehaw.org

And there are plenty of hidden cameras as well. I know for a fact that many of the portable signs that display your speed and flash a warning if you’re over the limit are ALSO able to read license plates and immediately alert the police. They were using it to look for stolen vehicles when I became aware of the system, but that was 7 years ago and all it takes is a little tweak to suddenly have a record of every car passing by.