Well. What can we say?
TFL say this:
"This is a dangerous, stupid and irresponsible act that could have resulted in serious injury or death to not only the individual concerned, but other passengers."
British Transport Police are urging the skier to get in touch so that they can "discuss the potential dangers of his stunt". Not quite convinced that that's going to happen.
Carry on with this Olympics bollocks and the next thing you know it'll be all tobaggon runs down the stairs at Covent Garden.