Next time, intervene bro. Containing anger is good, but standing by to everything isn't.
Whenever this kind of thing happens, if I try they say let it happen
I would say they're going to hurt someone, which one day I was too slow in seeing the very same kid make another kid bleed out his mouth and nose. So I don't see why they are still in public :S
I recognize them, too.
They are a sad bunch, I guess. :(