I thought about putting this in The Darwin Awards thread but I have to believe that as dumb as this was, the two guys who ended up rolling off of a cliff had every reason to believe that (despite visual evidence to the contrary) this was a safe activity.
The Darwin Awawrds are for extreme stupidity where the idiots in question end up dying at their own hands more or less...i.e. whatever killed them was their own idea and anyone else could see that it was likely to be lethal and (usually) both hideously painful and very, very public.