One could argue that catchers and pitchers communicating the signs, let alone the infielders, is also cheating. If the defense can communicate the signs, the offense should be allowed to try to decipher them (without the aid of technology or trash cans of course). Seriously though, I would LOVE to see a runner out at second just shout out the pitch to the batter when they figure them out. You want to really mess with a pitcher's head? That'll do it.