Utah_Saint

It's not going to be a long time. The NFL rules committee announced they were going to crack down on defensive holding, illegal contact and pass interference this season.

Mike Pereira made that tweet about the hawks not being looked at, when he was reporting on the rules committee meetings. There was no implication that the Seahawks were clean only that none of he examples given during the meeting were of the Seahawks.

Is NFL planning to get tighter on defensive holding and illegal contact? | Seahawks Blog | Seattle Times


In fact Mike Pereira agrees the Seahawks do hold and get away with it.

The Seattle Seahawks—the favorites to make the Super Bowl out of the NFC—employ an exasperating defensive game plan: They blitz rarely and drop an army of defenders into pass coverage. And those defenders mug, obstruct and foul opposing receivers on practically every play.

Quietly, the Seahawks have achieved a 13-3 record and home-field advantage throughout the NFC playoffs by exploiting a loophole: NFL referees are reluctant to throw endless flags for pass interference and defensive holding, even if defenses deserve them.

"They look at it and say, 'We may get called for one but not 10,'" said Mike Pereira, a former NFL vice president of officiating who is now a Fox analyst.

The Seattle Seahawks Defense Relies on a Brazen Tactic: Rampant Interference - WSJ


It's not just people perpetuating the "rumor", it's generally accepted by the major sports news outlets.

Secret Dance of Pass Interference - Flem File - ESPN

Kevin Gilbride: Seahawks have perfected art of pass interference - CBSSports.com

There are dozens more stories by smaller sports media sites and bloggers.

That's probably why people perpetuate the story.