I told off the teacher once- he was terrible, boring as hell, and one day I was in terrible mood and really pissed at him. I didn't curse him off, I just went on for about 90 seconds about how he was a bad teacher and everyone hated him. Thing was, he couldn't do anything because I had straight a's and hadn't broken any of the rules. He just told me to sit in the back of the room and wouldn't look at me for rest of the week. Its so much better to control yourself, you always have the upper hand if you make the other person mad and act like its all below you, plus you don't get into trouble that way.