AFAIU, the San Francisco peninsula (San Francisco + San Mateo counties) has one of the densest networks of ALPRs in the country. You can't drive more than a mile or two in the peninsula without passing an ALPR. And my educated guess is this is a response to the rise of property crimes, including car break-ins and theft, over the past 15 years, which became a huge political issue, locally and of course nationally. Those crimes began to drop precipitously after it became evident that criminals were being tracked and apprehended by the cameras, and I doubt it's a coincidence. IOW, at least in this region the cameras exit because of crime, and they're working.

That's not a defense of these wide ALPR networks, and certainly not a defense of how they're managed. But my point is that it's a thorny political issue because in many areas they actually work, at least to some significant degree. Whether or not they're worth the privacy cost, or whether or not alternatives would work sufficiently well, are fair questions, but precisely because they're fair and contentious questions means preventing their use won't be easy politically. Many of politicians and LEO officials pay lip service to privacy concerns, but behind the scenes they're wary of doing anything that would rollback the capabilities these systems provide.