Broadcasters say hesitancy by some CBS network affiliates to air a Sept. 11 documentary next week proves there has been a chilling effect on free speech rights since federal regulators cracked down after Janet Jackson's breast was exposed on TV in 2004.

Actor Robert DeNiro hosts the award-winning documentary that began as a quest to follow a rookie firefighter on an ordinary day, but resulted in the only known video of the first plane striking the World Trade Center. It includes profanity and some horrific scenes.

Several dozen CBS affiliates have decided to either replace the documentary or delay its broadcast until after 10 p.m., when the Federal Communications Commission loosens restrictions — even though the film has already aired twice with little controversy.

"This is example No. 1" of the chilling effect over concerns about profanity, said Martin Franks, executive vice president of CBS Corp.

"We don't think it's appropriate to sanitize the reality of the hell of Sept. 11," Franks said. "It shows the incredible stress that these heroes were under. To sanitize it in some way robs it of the horror they faced."

In testimony before the 2nd U.S. Court of Appeals last week regarding the FCC, lawyer Carter G. Phillips mentioned the documentary to show the court how timid broadcast companies had become since the FCC toughened its position toward profanities after the 2004 Super Bowl halftime show on CBS, when pop singer Jackson's breast was briefly exposed during a song.

Recently, Congress boosted the maximum fines the FCC can impose for indecency from $32,500 to $325,000.

The announcements to postpone or replace the documentary come as the Tupelo, Mississippi-based American Family Association readies its 3 million members to flood the FCC and CBS with complaints after the documentary airs, an effort that may trigger a close examination of the program by the FCC.

"This isn't an issue of censorship. It's an issue of responsibility to the public," said Randy Sharp, director of special projects for the group that describes itself as a 29-year-old organization that promotes the Biblical ethic of decency in American society.

"It's a documentary," he said. "It shows firefighters in action and other people during the very frantic time of the attack on the twin towers. We know how terrible it was. We don't have to be reminded of how we felt."

The documentary first aired on the six-month and one-year anniversaries of the Sept. 11 attacks on the trade center and the Pentagon. The latest showing will be on the eve of the five-year anniversary. It includes new interviews with many of the firefighters featured in the original program, describing how their lives have changed.

Franks said it was an easy decision not to edit the language in the documentary. "It was a much more difficult decision five years ago when the emotions were much more raw and fresh," he said.

Franks said it seemed "dishonest somehow" for the network to cover up the real language five years later because of the current regulatory environment. "What's frustrating is the chilled environment in which we are having to operate," he said.

FCC spokeswoman Tamara Lipper said the commission routinely takes context into account in any decency analysis. "Context is always important," she said. "We don't police the airwaves. We respond to viewer complaints. We haven't seen the broadcast in question. It's up to individual stations to decide what they should air or not air."