Machine, the 1st amendment was put in place to cover way weightier issues than what someone aught to have the common sense to know. Or at least what the adults in a society aught to have the common sense to know at least.
Yet common sense seems to be more elusive than the higgs boson.
Once again, someone walking down the street with the boxers showing, does not really effect you. You should use your freedom the think person dumb, and not associate with them. It is not wise to insist that police take action against such nonsense, as someday they might take action against you for something equally as silly.