NFL scouts and spies can watch defensive signals, jot down notes, even speak into recorders. But no videotaping allowed.
www.espn.com
From the link :
NFL's no-video rule
The "Game Operations Manual" states that "no video recording devices of any kind are permitted to be in use in the coaches' booth, on the field, or in the locker room during the game." The manual states that "all video shooting locations must be enclosed on all sides with a roof overhead." NFL security officials confiscated a camera and videotape from a New England video assistant on the Patriots' sideline when it was suspected he was recording the Jets' defensive signals. Taping any signals is prohibited.
Scouts funnel these observations to their teams' offensive coaching staffs, hoping to link the opponents' defensive signals to specific blitzes, fronts and coverages.
It's all legal under NFL rules, with one stipulation: absolutely no video recordings allowed.
Looks like there's plenty of confusion around this issue, mostly yours it would seem.


Further advances in technology, combined with football’s winking culture toward espionage, promise to confuse matters in what may already be the biggest cheating scandal in N.F.L. history.
www.nytimes.com