[Paul K]

Make them clean it up, make the parents take a more responsible role in the kids lives and stop the idiots supplying them with the cans of paint, marker pens etc
The kids need to accept the punnishment for their actions but parents need to accept some blame for allowing their kids to continue behaving like this. Too many parents let their kids just wander the streets at night because it is easier and far less work than making them stay home to do homework etc.