Interesting times, there has always been the rogues, vandals etc. It seems more widespread these days, as if there is no respect for self or others. As in persons or belongings. There almost seems a defiance in the youngsters.
Is it the parenting, the food or what they are exposed to on telly or the net. As a nipper is was always scared if I did anything wrong because of the consequence of getting my old mans leather belt across my bare back-side.
I think a lot of it is the knowledge that there's a lack of consequences. They know that if they get caught they'll basically just get a slap on the wrist. Kids are very clever & knowledgeable about all sorts of things, but that knowledge doesn't come with the experience you have in later life so it's more reckless and also more self-centred.
Even as a very young child you know what you can get away with. When you are little, you know just how far you can push your parents - what you can get away with, where that line is drawn. As you get older it's school - which teachers classes you can mess around in etc. They'll know that the law can't really touch them until a certain age for these sorts of behaviours, so they just do what they want without any concern of the affect it has on others.
I know in certain cultural backgrounds there is a lack of male role models within the family and it can affect behaviour (I have family & friends in teaching & this is something that they have to deal with a lot), but it isn't all down to that. Not all kids from broken homes turn to gang culture or general yobbishness & I'm sure there are plenty from stable family backgrounds that do.
Maybe there is something to be said about the lack of freedom kids have when they are young. We were always playing out, going to the woods & up the canal, we had responsibilities as to when were could go, what time we were due back, who we should tell if we were going far. Many kids these days aren't allowed any further than their back gardens (if they have them) and many don't even walk to & from school when they are young, so it's not surprising when they do get to an age when they are allowed certain freedoms that they don't know what to do with them & how to behave socially.
I don't suppose there is any 'on size fits all' solution either. Sometimes it's up to the individual child.