Well go oldschool and if they get out of hand toss them off the moving train. They would stop instantly if they got a real punishment for their actions. Hell the passengers should do it personally if the faggot that run the trains are so afraid of a lawsuit an unknown rider could take action personally. Hell pull a knife and a MAN just grabs his wrist and stops him instantly. This is what used to happen in the recent past a few decades ago but people are so tame they are scared to do the right thing. Hell disarm and spank his bare ass in front of everyone since his parents raised him terribly.