A New England Patriots employee was caught violating NFL rules by videotaping the signals the Jets’ coaches sent in from the sidelines at the Meadowlands on Sunday. Now the league needs to act.

NFL Commissioner Roger Goodell has earned a reputation as a strict disciplinarian, and he must come down every bit as hard on the Patriots — and, specifically, coach Bill Belichick — as he has on NFL players who acted as though the rules didn’t apply to them. Goodell needs to dock the Patriots a first-round draft pick, fine the franchise a significant amount of money, and suspend Belichick for at least one game.

That might seem like an overreaction for a violation of a rule that most fans never knew existed. After all, some fans will say, NFL teams constantly scrutinize game film of everything that happens on the field. What’s wrong with also filming the sidelines?

Here’s what’s wrong with it: It’s against league rules. It’s just as much a violation of NFL rules as sending spies into the other team’s locker room, disseminating false information on injury reports, or paying players off the books to circumvent the salary cap. The Patriots were cheating, and they have to be held accountable.

That accountability needs to begin with Belichick. Just because Belichick is the best coach in the NFL — and he is, by a large margin — doesn’t entitle him to the benefit of the doubt in this situation. Belichick has total control over the franchise and must have known this was going on. Merely fining him isn’t enough. Goodell must suspend him.

It’s still not clear exactly how the Patriots gained an advantage through videotaping the Jets’ signals, but they most likely compared what they saw the Jets’ defensive coaches signaling on the tape to whether the Jets subsequently blitzed and what kind of coverage the secondary used. Then, when the Jets used the same signals later, they could have adjusted their offensive play calling accordingly, or told quarterback Tom Brady through the headset in his helmet what kind of defense he was likely to see on the next play.

The Patriots’ cheating is particularly egregious because the team had previously been warned about taping the opposition’s signals. Packers president Bob Harlan said the same Patriots employee caught red-handed against the Jets on Sunday was also caught taping the Packers’ signals when the Patriots visited Green Bay last year, and that the NFL subsequently told the Patriots to knock it off. Detroit Lions president Matt Millen said he believes the Patriots did the same thing against his team last season. San Diego Chargers running back LaDainian Tomlinson (who last year famously said Belichick and the Patriots have “absolutely no class”) said in a radio interview yesterday that he had heard similar allegations about the Patriots.

Goodell surely hopes he can find a middle ground in this case, some way of enforcing the rules without acting too harshly toward one of the league’s most popular and successful franchises. Suspending any head coach would be an extraordinary move, but punishing a future Hall of Fame head coach, one who has earned three Super Bowl rings in the last six years, would send shockwaves through the league. Furthermore, taking a first-round draft pick or millions of dollars away from the Patriots would anger Robert Kraft, one of the league’s most influential owners, and the owners, after all, are the commissioner’s boss.

But just a slap on the wrist would send a horrible message, a message that teams can cheat to get ahead and get away with it. The NFL needs to act not only on what it discovered on Sunday, but also investigate when the Patriots started stealing signals and who was involved. Were the Patriots stealing signs in each of their three Super Bowls? Is Belichick one of the league’s great strategists because he cheats to find out what the other team is doing? Is Brady one of the NFL’s best decision makers because his coaches are feeding information into the headset in his helmet that quarterbacks on rule-abiding teams aren’t getting?

The NFL also needs to launch an investigation to find out whether other teams are doing this. It seems unlikely that the Patriots are the only team that has ever violated this rule, and if the league determines that other teams have broken the same rule, Goodell needs to come down hard on those teams, too.

The truth is, stealing signs probably doesn’t provide a great competitive advantage. Certainly, sign stealing can’t account for how much better the Patriots were than the Jets on Sunday. And stealing signs is an old story in sports. The baseball Giants are widely believed to have stolen signs – and, by extension, the pennant – from the Brooklyn Dodgers in 1951. Some Brooklyn Dodger fans are still furious about that, but at the end of the day, the Giants still won the pennant.

And the Patriots still won their three Super Bowls. New England has had the best team in football this decade and is the odds-on favorite to win it all again this season. Goodell needs to put a stop to the Patriots’ shenanigans now to ensure that if they’re back in the Super Bowl in five months, no one questions the game’s integrity.

Mr. Smith is a writer for FootballOutsiders.com