Yak Skiing

Now this is what I call an extreme sport. How cool is this! Tying yourself to a 2 tonne ranting, steaming ball of hair and sinew. Creating a primitive pulley round a tree and then getting it to basically charge at you (the yak, not the tree). Then I guess you just better stay on those ski's.

It raises so many questions, like:

Who says satellite television doesn't educate? This hill famer had to get the idea somewhere.
What happens half way up (surely you have to meet the mad yak at some point).
What is stopping the rests of the herd from charging?
How much does it cost?
What's the Apres-ski like?
Would it work with the Milka cow?