The guy needs to calm down. Now, if I remember correctly, there were atleast two other kids that could've wailed on that guy's back while he pinned down a friend. He's very lucky they chose not to by respect, were cowards, or didn't want even smaller kids to see.
Anyways, he was being a tightwad. Let them try to do their tricks.
QFE
IT wasn't even his property, he had no right to tell them to leave. He was wrong, not saying the kids weren't, but he has no control over them. The fact that he attacked the kid trying to take his skateboard is one of the most immature things he could have done. He doesn't deserve to be a father, his kids'll probably grow up hating him. I hate him and I don't even know him.