Yes, it's a very big problem. Violence and alcohol from an early age, coming from bad/poor households, its pretty bad. It's not like gangs, more just a large uneducated violent subculture. I avoid them if I can, if you don't look like one of them, you are pretty much garenteed some abuse, verbal at best, physical at worst. I've been chased with rocks before just because I looked like a goth, cause I my hair is dyed red.
Our house is also under frequent rock attack because we are gay. Calling the police just aggrevates it because its against some sort of community code, they look out for each other. It's not just kids though, this attitude can go with them their entire lives.