I think of license plate readers like I think of all the new "features" from Apple or Google. The idea behind an LPR is they're only catching criminals, solving crimes, or giving you a fix-it ticket for your expired registration. The idea is "if you aren't doing anything wrong you have nothing to fear". Apple (and others) do similar... they add all these features for location tracking, family sharing, etc. But they only work if you're on the up and up. Imaging the guy that's cheating on his wife. If he has Location Services enabled and Find My sharing then he's going to get caught. If he turns them off, it raises questions and doubts. Or what about the guy that's buying something from his dealer? Or sometimes its even the innocent thing where he's buying jewelry for his wife but she sees him at the jewelry store. All these "features" work off the assumption that you're not up to no good... that you aren't buying weed in a state where its still illegal... not cheating on your wife... not driving with your tailgate down cause your tags are expired cause you lost your job... not at the bar when you said you were at the AA meeting.