Round-up all the scum of the Earth, and make them walk inside giant Hamster wheels attached to generators
Hey! you may be on to something there, the uk would have a readily renewable resource - Yobbos!
Certainly beats the hell out of asbos, hoodie bans and fully paid 'rehabilitation holidays'.
a month of 10 hour days in a hamster wheel would sort em out AND they would be doing something useful :D