Without a doubt, there are packs of kids roaming the streets of the UK at the moment who are feral.
Psychological lab tests over the years have proven that if people are not given boundaries (specifically when it comes to administering pain to others), they will continue to inflict more and more pain. They come to enjoy it, and their sense of empathy is greatly diminished.
I'm not sure if modern kids/adults are any more inherently feral than other generations before them, but it's the current complete lack of censure that has made them worse.
Some kids no longer seem to understand what shame is. No one tells them off in the street any more. If they go before the courts, it's a badge of honour for them .. one they proudly wear when they're let off with nowt more than a mild rebuke.