It's a tired old story, cutting a Banksy out of the wall. And most of the time, the piece has to be cut out of the wall.
But Banksy's Waiting In Vain piece was done on the shutters next to the strip club. So why these dudes cutting the piece out? Why not just remove the entire shutter--seems like a much better background than an out of context chunk of metal.
But then again, that's the argument against moving street art from the street--once you do, its out of context.