OK, this is way too enjoyable than it should be, but this is the sort of problems that I love to read about, not about the creation of the universe, for heaven's sake! :)
Wired Science is investigating, using simple mechanics, whether the stunt of wall climbing by these two people, is even possible.
You can follow the simple statics workings that was shown. In the end, using the premise that was presented, the force being applied by each person is just too much. But does that mean that this stunt can't be done, or that the picture is a fake? Does the fact that the guy on the right is actually pushing with his toes gave it away?
What do you think?