The most important thing when it comes to the unavoidable (one's bound to encounter rebels when teaching teenagers, there is no escape from chaos - it marks us all) is to react immediately. Not for us Obama-like approach, no, we have to be swift and smooth and deal with the rebels changing them into the paragons of English students ;) Or at least try - because in order to change our students (or rather their attitude) we must try to understand them... and it's not easy, trying to understand people who don't understand themselves!