We have a generation of youth who were not allowed to be disciplined at school or by the police without outrage from 'human rights' groups and 'anti-smacking' do-gooders and as such see themselves as untouchable. As with all things in life, if there are no discernable boundaries then people, especially young men, will keep pushing until they find the boundaries of acceptable behaviour - that is why they get to the stage of happy slapping, then knife attacks and the first boundary they meet is being arrested for assault, manslaughter or murder.
This is certainly not about endemic poverty - they come from a generation that wants it all and has it all - now - without waiting, and the lack of parental control just makes it worse. The kids lack direction, either from their parents or the government and are looking for thrills and kicks from either drugs or violence or both - the inevitable consequence is an increase in crime as they lack respect for the society which appears to have failed them.
The answer? maybe cutting the goolies off will sort some of the boys out, but what about the girls who are just as bad? Some sort of national service might help, we could send them out to do humanitarian work in the properly deprived areas of the world.
If we could stop pandering to the minority of lefty, liberal 'intellectuals' who keep telling us that the rights of the individual are paramount and go back to the proven concept that the rights of the majority must be respected at least as much if any society is going to function properly, then we might start to reverse a very dangerous trend that has taken us a long way down a dark path.