Eleven years after its birth as a strange stepchild of the response to the attacks on 9/11, the 9/11 Truth movement remains firmly confined to the political fringe. But the truthers retain the ability to rile people up, and on Tuesday a half dozen of them took their case to the Lower Manhattan neighborhood in the shadow of the rising Freedom Tower.

There, the truthers absorbed the abuse of passersby. “You want to be on Hitler’s side, go on Hitler’s side!” one man, Ronald Lefranc, yelled at them. “We are not here for you to fuckin’ open your mouth and protest!” shouted a woman who wore red, white and blue and carried an Army camouflage bag.

The truthers in Zucotti Park,the site of the original Occupy Wall Street encampment, were unfazed. They are as certain as ever that the attacks of September 11 were an inside job, despite a total absence of credible evidence for a massive and complex conspiracy involving hundreds of players in the American government, the private sector, and Al Qaeda alike. They’re also by and large convinced that their movement is growing and strong, despite the fact that it’s become a closed loop of groups and characters who have been going over the same theories, producing similar documentaries, and visiting the same websites for years.

“I’ve convinced a lot of people to look into this,” said Carlos Beltran, one of the protesters out in Lower Manhattan on Tuesday. Beltran is from Fort Worth, Texas, and attended protests in Tampa and Charlotte during the conventions.

Beltran said he “doesn’t ascribe to any theories — I just look for facts.” He held a sign that said “Ask me about Building 7 — 47 story building NOT hit by a plane.”

“I think the movement is definitely speeding up,” said Alex K., a reedy young protester who didn’t want his last name used. Alex hails from Ohio but lives in New York now. “A lot of people go comment on news stories online — that’s what I do. We try to wake people up.” Alex said it was his first time visiting the area where the towers fell on the anniversary of 9/11, though he became heavily interested in truther theories two years ago.

Alex, like other Truthers BuzzFeed spoke with, cited a study that showed that nearly 50% of people in New York State doubted the official narrative of events. But the study, conducted in 2004, was sponsored by 9/11 Truth organizations including 911truth.org.

In fact, polling has shown that many people believe the government either bungled the run-up to the attacks or was hiding something, but relatively few believe that it was a staged event from top to bottom. A New York Times / CBS News poll from 2006 showed that 53% of Americans believed Bush administration officials were “mostly telling the truth but hiding something” about what they knew before the attacks, while 28% believed they were “mostly lying.” A Scripps Howard poll conducted by Ohio University in 2006 showed that 77% of respondents thought it “unlikely” that bombs had already been planted in the Twin Towers, and 59% found it unlikely that “federal officials either assisted in the 9/11 attacks or took no action to prevent them because they wanted the United States to go to war in the Middle East.”

The Truth theories are doing somewhat better internationally: a 2008 poll conducted by World Public Opinion in 17 countries had 46% of respondents believing that Al-Qaeda was behind the attacks, while 15% thought it was the U.S. government and seven percent thought it was Israel. Respondents in the Middle East and Europe especially doubted that Al-Qaeda perpetrated the attack.

Another fact cited with pride by truthers: a Denver PBS station recently played a documentary called 9/11: Explosive Evidence, lending credence to the idea that Truther views are becoming mainstream.

“I believe we may have reached a turning point with PBS in Colorado broadcasting an abbreviated version of 9/11: Explosive Evidence,” said Jim Fetzer, the Wisconsin- based founder of Scholars for 9/11 Truth.

Fetzer describes the events of 9/11 as “completely unrealistic” and says that when he saw the towers fall, “I knew this was a fantasy but I said to myself, how am I going to make myself heard?”

His group is one of many that have sprung up around the conspiracy theory in recent years, since radio host Alex Jones went on air the day of the attacks saying that the Bush administration had manufactured a terrorist attack (as he had predicted). There are now Firefighters for 9/11 Truth, Architects and Engineers for 9/11 Truth, and others.

“I think it’s growing — we have more factions now,” said Richard Borkrowski of New York, who saw one of the many 9/11 truth-related documentaries five or six years ago. (“It got me thinking. Before that, I believed everything”)

Truthers believe that the current state of the economy and turmoil abroad encourage people to join their movement.

“Problems just keep happening and happening, and people are more open to believing our message, which has been hard for people to accept,” said Ken Jenkins, a video producer involved in Bay-area Truth movements. “The shock and awe of the 9/11 event itself, which was intended to so terrorize people that they wouldn’t question it — now’s that’s kind of worn off.”

Graeme MacQueen, a retired Canadian professor who runs a truther publication, says that although 9/11 Truth is a “huge global social movement,” it flies under the radar because “it’s not a traditional social movement. It’s mostly people who aren’t publicly visible who are connected through the internet and so on and so forth.”

The most publicly visible member of the movement at this point is Jones, who has turned trutherism into an empire (after initially losing most of the radio stations that carried his show) and spent most of Tuesday’s show talking about “the 20 smoking guns of 9/11.”

Jones’s radio show connects the various Truther factions, and is commonly cited as a way people got into it in the first place.

But other than him, the movement has morphed into one resembling any other conspiracy theory — small, relatively obscure, and dismissed by the mainstream.

What separates the truthers from people who believe in alien abduction and puts them more in league with the more-current birthers is their ability to shock and offend.

In Zuccotti Park on Tuesday, Alex K. admitted that he felt a twinge of guilt about protesting so close to the site of the attacks, as angry pedestrians came by one after another to argue with the truthers.

“Yeah I mean, that’s a concern,” Alex said. “We want to get the message out without offending people who lost loved ones.”

Borkrowski didn’t feel the same way.

“There’s places here for people to mourn,” he said.