I think they were siblings - the word brother was mentioned, but not sure who was sibling. Friends of siblings and siblings, will always wind eachother up.
I just think that child needs something, to be like that in the first place, to be capable of that much hysteria, is not right. He is definately obsessed with it, in a very unhealthy way, too.
My son isn't allowed longer than 1 1/2 hours tops, on computer or consoles and not allowed every day either. He probably gets on computer once a week, if that and his games consoles about the same.
If I were his parent, I would be having him referred to a specialist of some kind for therapy.
Kids don't stop winding another up when they know it works - siblings like that, will do that unfortunately.
If it wasn't all staged for the effect of the video, which I don't think it was, then he could have been discussing his family annoys him and he wants to be on there left alone - then he could be being told what to do and how to behave from people on myspace. He won't let anyone see what's going on, so that's not good to start with.
I would be taking that computer to find out, if it were my son.