That's not to say you shouldn't partake in them. Just that safety, not getting buzzed, should always be your first priority. Thankfully, these revelers are here to show us what not to do.
They broke the first rule of keg stands! Don't drop the person doing the keg stand. That's like the only rule. Come on, guys. Although, I don't place all the blame on the two guys. It looks like she fidgeted out of their grip a bit. Also, these people were probably hammered, because I've never seen someone actually drop a person until today.
[H/T Bob's Blitz]