Arrest them for indecent exposure and make them register as sex offenders for life
Y’know what? That’s a really good idea. Seriously. They make a choice to be assholes (no pun intended) for ten seconds, and are marked for life as sex offenders, having to register every time they relocate, and knowing that every background check for a job will identify them as a sex offender.
Time to quit ignoring these people. Got to make it hurt.