His real name is Thomas Bruso, aka Tom Slick or Vietnam Tom or Epic Beard Man. Apparently he's a very unstable and dangerous man and a police hater. The AC Transit bus ass-whooping isn't his first Youtube incident. Here's a video shot in August 2009, where he got taserd by police at a game in Oakland for resisting arrest: http://www.youtube.com/watch?v=sOkeafCVtTE
http://www.youtube.com/watch?v=sOkeafCVtTE