You're nuts, this kid didn't mean anyone any harm.
No wonder you're so anti gun, you assume everyone is as mentally off balance as you are.
One, he is not a KID, he is a man and two, of course he means other people harm, that's the whole motivation behind his shtick. He is attempting to make other people a joke, to make them look silly, to harm their self esteem if you will, he is an embarrassment to himself. Like I said, the appropriate response was the actions of the last guy on the video.
You obviously fail to grasp basic psychology if you think that behaviour is harmless. The very first think I am going to do if I want to get into someone's head is to razz them up a bit, give them shit and see how they handle it, if they react passively, I know I have an easy target on my hands, from their I could literally order them to give me his shoes or the shirt of his back, if he reacts assertively or aggressively, I know I have someone with some self respect and to dominate them will be a greater challenge.
This is classic bullying, and it is any wonder american kids go of the rails and shoot up schools if you think behaving like that is somehow normal.