>But cops have been tracked down and killed by people using apps like Waze so it's not a completely unwarranted fear.

Sure, but you haven't made the case for why the fear is anyone else's problem. If a person is too scared to be a cop there's an easy fix: stop being a cop. Unfortunately, regular citizens who can't afford to up and move to a country that has civil rights (that is, most of them) don't have the same recourse.