For some reason I have been fixated on license plate readers (probably not a bad parallel to Palantir?). Plenty of people on HN justifiably decry license plate readers due to their violation of our privacy (to be sure there's an argument to made though since you are technically "in public" when driving — your privacy protections might be on shaky legal grounds).
But if license plate readers are already a reality (we know they are), why should only private actors have that data? This would make sense if we completely trusted those private actors, of course.
The opposite could be a public, open-source license plate reader that caught on (people using dash cams + open software) — the data sent to a collective, public database. (Perhaps the software strips out personal license plates — only logging tags of official or government vehicles?).
My first reaction is the degree to which that could be abused by ... stalkers? Truly a bad thing. But then I ask myself to what degree the private license plate readers are perhaps "being abused" (or will be more and more) and we don't even know about it.
As I say, a thought experiment that I find myself seeing merits both for and against.