A few things here. First off, the daycare workers in that place suck. My firstborn was in daycare for a while. If as so much of a scratch was on him, the workers had to fill out an incident report. Even if my kid fell down on the playground and bruised his knee. If my child had come home with any kind of injury no matter how small and there was no explanation, the daycare was in serious trouble. Also, at my sons daycare, there were multiple adults in every room so nothing could be overlooked. Each age group was also separated. A 9 year old would not be in the same room as an infant. Ever. That daycare sucks....but I'm guessing it's cheap as hell and the workers get paid shit wages. Thats the difference between a 900 dollar a month daycare and a 200 dollar a month day care.
Second, the child is seriously messed up. I suspect he resorts to that kind of violence because he either sees it at home, was abused himself, or is in an environment where violence is rewarded. *Its cool to be the bully, beat up, steal, gangbang, etc...* What that kid needs is a change in living conditions. Unfortunately, I suspect he will continue on his path of violence and become trash of society. Very sad video.