In the United States, there is no expectation of privacy while in public. They are not legally obligated to do anything. This doesn't make it any less of an as

In the United States, there is no expectation of privacy while in public. They are not legally obligated to do anything. This doesn't make it any less of an asshole behavior, though. Also, it should not be the onus of each target of your gaze to constantly be saying "stop it". That's called "opt-out" and is pretty globally regarded as completely obnoxious.