I recently discovered a company called Flock which apparently is building a massive surveillance network. I came across a reddit post on r/sysadmin where an admin received a request to install a black box device so that law enforcement could access cameras.
https://en.m.wikipedia.org/wiki/Flock_Safety
https://www.aclu.org/news/privacy-technology/how-to-pump-the-brakes-on-your-police-departments-use-of-flocks-mass-surveillance-license-plate-readers (disclaimer: I don’t support the political views of ACLU)
I maintain a program called Assassin that has an ALPR camera database as a headlining feature. You install it on a low-power SBC (like a Raspberry Pi) in your car, and it notifies you before passing ALPR cameras (among other threats). I only personally maintain the database in my states, but I like to think it’s fairly comprehensive.
With some technical experience, you can create a pretty elegant system with concealed status LEDs, configurable audio alerts, and more.