My best friend had a couple of classes like that (he has taught from 5th grade to HS over a 20 year period in a NJ public school). He laid down the law Day One that madness would not be tolerated, and he said 95% of the trouble in class was squashed with in two weeks. That teacher let the inmates run the asylum. Yes my friend is male, but he isn't physically imposing. He also has a school disciplinarian that generally backs the teachers...and I know that is a big issue in many schools. Because of that, yes S.R.O. are needed,but his behavior wasn't.

That said, my friend and I also question that this video is real.