Of course.
http://www.coldhardfootballfacts.com/Articles/11_3994_With_Belichick,_NFL,_it's_all_about_the_fi lm.html
Belichick the innovator felt the backhand of the regulators in 2007 when the NFL fined him $500,000 for videotaping the New York Jets coaching staff sending plays to their defensive players via hand signals. But Belichick hardly was the first, nor will he be the last NFL coach to make such use of video.
In his 1986 book, They’re Playing My Game, former Kansas City coach Hank Stram openly noted that during a playoff game between the Cowboys and the Los Angeles Rams that he was broadcasting that “[e]yes and TV cameras follow the action upfield, all except the camera fixed on the bench of the team opposite our vantage point. Its operator keeps the viewfinder trained on the far sideline and the zoom tight on the two assistants who motion signals to the quarterback on the field. One of them is really signaling, the other is a decoy. Both are being filmed. Later the footage of their signals will be painstakingly matched with the plays to which they correspond, then analyzed, cross-referenced, and the signals decoded.”
In his preview of the 2011 NFL season, Sports Illustrated’s Peter King wrote that a defensive coordinator for an NFC team “says his video crew reviews telecasts and transcribes the presnap calls of opposing quarterbacks, and pairs those with the play. The information is analyzed to see what patterns can be discerned.
“It’s perilously close to what got the Patriots in hot water during Spygate,” King added, “but because the audio is available over public airwaves, there’s no NFL rule against it.”
Indeed, in 1980, Sports Illustrated’s Paul Zimmerman wrote a story entitled “The Stolen Signals Caper,” in which Houston Oilers’ linebacker and defensive signal-caller Gregg Bingham claimed that the key to his team’s collection of five interceptions from San Diego quarterback Dan Fouts and resulting 17-14 playoff upset of the Chargers was the ability of Houston defensive coordinator Ed Biles to decipher the hand signals that San Diego used to transmit the play from the sideline to Fouts.