That youtube 'hoax' is priceless, as in worthless, as in WTF!
A hoax is an elaborate tale intended to misguide someone into believing something that is fabricated. Youtube showing videos upside down is far from a hoax, it's a childish annoyance that only the most unimaginative marketing gimp would come up with.
They should have done a dozen subtle things instead, things that you might not pick up on right away, like have some featured 'spoof' videos, fake video footage of giant muppets like we had last year for no reason. Turning things upside down is retarded, boring, and it makes my blood boil.