What's up with 'happy slapping'?

Tweet

I was appalled to read in the newspapers a few days ago that teenagers are 'happy slapping' others in order to celebrate a friend's birthday. This 'happy slapping' sometimes even results in serious injuries. And what is up with groups of young teenagers (aged 13 or 14) beating their classmates up just because they are not happy with these classmates or friends. What's haoppening to the young today? I'm really saddened by this....Is it happening everywhere?