Here's a picture of Mark Renshaw headbutting Julian Dean in the final sprint of today's stage of the Tour de France. Renshaw was disqualified from the stage
and kicked out of the entire race for this:

Oh... wait... that's Robbie McEwen headbutting Stuart O'Grady in an earlier Tour de France! McEwen was disqualified from the stage for
his headbutt, but was
not kicked out of the Tour. Harsh on Renshaw?
Also, what is with these Antipodeans headbutting each other all the time? As Chopper Read might say, settle the fuck down!