In a sidebar to that Banks piece Clayton weighs in with:
"Teams are always trying to steal signs and signals off other teams. That's just football."
He should have said that's just football, unless Belichick is your opponent.
Clayton was on with Felger about two weeks after sypgate broke, when all the talking heads were starting to backtrack a tad, and he told Felger that he had spoken with sources who knew for a fact that at least three teams in the league were currently (2007) using video taped defensive signals in game. He said those teams synched up the video to the polariods taken pre snap at halftime and made exceptional second half adjustments - that was one of the keys as to who was doing it.
Felger challenged him that he didn't see how it could possibly be done. Not enough time at the half. Clayton said one team had two dedicated defensive assistants on computers in a training room waiting for the information which was burned onto a CD in less than 6 seconds. As familiar as they were with the information it took them about 20 minutes to have it all decifered, and the information was in the hands of the DC on the field roughly 12 minutes into the second half (in real time, not game clock time).
He made a point of telling Felger that the Patriots were NOT one of the teams.
I doubt you could pry the names of those teams or his sources out of Clayton with a congressional subpoena. Media including ESPN only surrender sources that don't give them the information they want or when it suits them...