The same sort of people that drop lumps of concrete onto trains passing under bridges, that heave paving slabs at cars from motorway bridges and who lob bricks at a man and kill him for telling them to be quiet and to stop bullying his children.
Bring back Corporal Punishment in schools, bring back Borstals, bring back the death penalty, bring back National Service.
Will that mean the end of problems like this? No but it will give many of us a sense of satisfaction that at least something is being done.