This isn't really "outside the box." Valve has been doing this for years with their games (Team Fortress 2, Left 4 Dead, etc.) If you cheat, you're banned from playing on any server that has the "anti-cheat" flag set, which is most of them... so you're stuck playing on a few servers mostly populated with other cheaters.
The only difference I can see is that, in Valve's system, non-cheaters are allowed to play with cheaters, if they want... you can even activate cheats, play on the the cheat-enabled servers, then disable the cheats and go back to the main servers again, because you only get banned for cheating on an anti-cheat server.
The website, like the press conference, is designed to confuse people, but only temporarily. This is where it differs fundamentally from the material that trademark law is designed to prevent -- the Yes Men WANT to be found out. That's how they get their message out. It doesn't do them any good to really trick people into thinking that the Chamber of Commerce has changed its stance on climate change; they want people to believe it only long enough to be outraged when they discover that the real Chamber hasn't actually done anything at all.
There's nothing in law to indicate whether this sort of use of trademarks is (or should be) protected, and (not that I'm a lawyer, but) I know of no case law on the subject.