I'm a moderator on a bike forum. Probably 10,000 plus members and you get to know guys pretty well. I'm thankful that I only knew this guy vaguely.
http://www.modbee.com/news/local/crime/article38446845.html
Shy of having a pair of dykes handy, I think this would be game over. I don't even think many could get it off with a knive. Especially if while still being attacked.
Ill ll up date this as more is learned.