I'd admit it was stupid for the Pat's to continue videotaping on the sideline after ALL NFL teams were warned to discontinue the practice, but it is even more stupid for the reason that there really is no competitive edge gained by the practice. It's just as easy for someone on the sideline to visually observe the defensive signals given by the other team and chart them, which is not against NFL rules. The reason you see coaches shield their faces with their clipboards sometimes is because they know people are watching.
The signals are changed from game to game and there are even "dummy" signals being given to try and confuse the opposition as to what the actual signals are. The videotaping is something Bill likes to do so that when he is watching the game film he can try and look for "tendencies" from the opposing coaches for the next time they play them. The signals he sees WILL NOT be used again by the other team. If they do use them again they are fools. There is no way that the taping of the signals could be used during THAT game to gain any competitive advantage. That's why I think it was dumb of the Pats to take the risk in doing it.
With that said, they got caught, they will own up to it, take their lumps and move on and still continue to dominate the league on the field. When you are on top and dominant, even in this time of the NFL trying to create parody in the league, everyone, including the commissioner and little Eric Man-Gina, will be trying to knock you off. They can't do it on the playing field, so they must attempt to do it by other means.