"Warn 'em on the ticket, control 'em in the cabin, and charge 'em to the fullest extent of the Law..." Post warnings in the departure lounge bars as well.
As part of rehabiltation after conviction, these passengers should be obliged to attend a cabin evacuation drills course, as most of them have no idea of what is involved.
Not enough passengers (and critics) realise that the captain's word is the law. If they don't feel that the command structure is "PC", dont fly, don't go on a ship - and I think the guard can throw you off a train if he sees fit.
Anyway, if the cabin gets rowdy, slowly raise the temperature and the cabin altititude. You'll have 'em sleeping like babies. Let the CC know of course!