Check out this video of teachers flipping out in the classroom. Now, the pinhead in the interview, Mark Eiglarsh, makes the nutty case that teachers yelling at bad behaving kids is "emotional abuse". Why is it people who apparently have not been a classroom in the last 20 years automatically line up against teachers? I graduated from high school (The Fightin' Cobras!) in 1994 and so many of the kids were just absolute monsters who simply did not want to be in the classroom. In the ensuing 13 (!) years, it can only have gotten worse. I'm surprised in this country that we don't have more teachers bringing bodily harm to their charges. Yes, wanton abuse from a teacher should never be tolerated, but the disrespect from pupils towards their teachers is rampant in a culture that too often tells kids that they're perfect in every way no matter what they do.
As to the use of cell phones in class, I sort of understand the need to have them in emergencies (Columbine comes to mind) but once they're in the building they must be turned off and not used. And if they are, out they go - no second chances.