There is a reason that most NFL home teams choose the sideline with its back to the press box and coaching boxes. There is a reason coaches hold the play chart in front of their faces when calling plays or coverages. There is a reason locker rooms are guarded and practice facilities are inspected for hidden cameras and hotel trash cans are emptied lest a morsel of information fall into the wrong hands.
The reason is not because Bill Belichick and the New England Patriots have turned the league into a cult of cheaters.
The reason is because the games are coached by human beings.