Initial Response
After footage from the actual tape was aired on Fox NFL Sunday on September 16, former Dallas Cowboys head coach Jimmy Johnson claimed, "This is exactly how I was told to do it 18 years ago by a Kansas City Chiefs scout. I tried it, but I didn't think it helped us." Johnson also said, "Bill Belichick was wrong because he videotaped signals after a memo was sent out to all of the teams saying not to do it. But what irritates me is hearing some reactions from players and coaches. These players don't know what their coaches are doing. And some of the coaches have selective amnesia because I know for a fact there were various teams doing this. That's why the memo was sent to everybody. That doesn't make [Belichick] right, but a lot of teams are doing this."
http://en.wikipedia.org/wiki/2007_National_Football_League_videotaping_controversy
It's all fine and dandy as long as you don't get caught. And, as Jimmy Johnson said, a lot of teams were doing the same thing the Patriots did. They just didn't get caught.