Genuine question: I’m someone who hates the centralization of data with companies like Flock. I also want safer streets. I have liked things like speed cameras and bus-mounted bus lane cameras specifically because they target the problem without the need for police involvement. How do you get the latter without ALPRs? Or do ALPRs indicate cameras specifically collecting license plates independent of active enforcement?
Right next to my apartment building is a crosswalk that crosses a fairly busy street. The crosswalk is well-marked, and it has a sign in the median specifically stating that stopping for pedestrians is required by law. In the time I've lived here I've nearly been hit by cars several times on this crosswalk, and I've witnessed countless people almost get hit here as well. Once I saw a pedestrian yell at the driver, and the driver yelled back that they didn't have to stop because "I don't have a stop sign".
I noticed recently that the city installed a flock camera pointed directly at this crosswalk, and while I'm generally opposed to this kind of surveillance, and I wish they would implement other measures to make this safer, I really would love nothing more than for drivers speeding through here and not stopping for pedestrians to get ticketed. It's unclear still whether that's actually happening (and not that it matters once you're dead), but I'm finding myself empathizing with the argument for more surveillance for the first time in my life.
ALPRs are generally just cameras that create searchable timestamped databases of identified vehicles, private or public. But they're only really useful for public entities, because they're the only ones who can in the general case do anything with a tagged car (look up who owns it, curb it, &c).