Off topic, but about beating people with scooters.
On the way down to the local, I have to ride through a park. This park is very deserted up the top, and covered very well. A couple years ago lots of kids walking through there get raped. I was really scared, and mum said if I wanted to go to the skatepark, I would have to find another way, because I usually ride down by myself. To this day, I ride down there by myself. The only thing that allows me to do so, is knowing that if I hit someone with my deck in a tailwhip motion, it will hurt like fuck.
I guess violence isn't really the problem to this. Go spy on them with a video camera and record them using it or take photos if you can see it but not steal it back, then take them to the police.