I don't think there's anything in the rulebook, but I always saw it as that gray area between trying to get an advantage and being classless. Kind of like when A-Rod yelled "I got it!" while approaching 3rd base against Toronto (I think) last season. It also brings up the age-old debate over playing the game "the right way". That being said, a large part of Spygate was over stealing signs as well. They were videotaped in advance and it's a completely different sport, but it's interesting how it can be so clean-cut in football and not in baseball. I guess I understand this. I guess I just think that the signs are used to disguise and if you aren't diguising well enough you should have to pay by having the other team know what your going to do.