I just watched this video, and I couldn't believe what i was seeing! First of all that kid has some serious freaking skills! Secondly I love that Green Day has lots of interactions with their fans. At that same concert i believe, he borrowed a scarf from a girl in the crowd, then had her come up on stage with him while singing "Are we the waiting" and he put his arm around her and they sang and swayed together. Some people are just so lucky.
http://www.youtube.com/watch?v=gf3kB5Ctjk4 this is the vid with the girl up on stage.