BOB GARFIELD: This is On the Media. I'm Bob Garfield.

BROOKE GLADSTONE: And I'm Brooke Gladstone. This week, a vast terrorist plot was foiled in London, but many questions remain about how and who and why. The age of terrorism is rife with questions, and even when there are answers, they don't necessarily persuade. A poll released this month by the Scripps Survey Research Center found that 36 percent of Americans believe that the U.S. government either sat back or assisted in the attacks on 9/11 because it wanted a pretext for war. Here is MSNBC's Tucker Carlson Wednesday, taking umbrage with a conspiracy theory.

TUCKER CARLSON: I get that. And I'm not in any way questioning your right to complain about the actions of our government. I'm merely saying it is wrong, blasphemous and sinful for you to suggest, imply or help other people come to the conclusion that the U.S. government killed 3,000 of its own citizens, because it didn't.

BROOKE GLADSTONE: The notion of government complicity has gained steam, in part due to a recently-formed group of academics, called Scholars for 9/11 Truth. The Associated Press notes that most aren't experts in the relevant fields, though they are well-educated. Meanwhile, a feature-length video, called "Loose Change," has become an online phenomenon by arguing that the Twin Towers were felled by the government in a controlled explosion. Mark Fenster is authority of Conspiracy Theories: Secrecy and Power in American Culture. He's not surprised that there is a vast number of conspiracy theorists out there, but he is suprised about one thing.

MARK FENSTER: What's surprising, I think, about these numbers is just how late they've arrived. The tendency for Americans, particularly in times of war and times when things aren't going particularly well, to believe in conspiracy theory is higher than the kinds of numbers that we were seeing immediately after 2001 and through 2003-2004. And it wasn't until later than that that the numbers began to really kick in.

BROOKE GLADSTONE: What accounts for that?

MARK FENSTER: Folks are reading backwards from events that have occurred since September 11th, like Iraq, like Hurricane Katrina, that might indicate on the one hand that the Bush administration is acting in a putatively evil way, and on the other hand, that they're acting in a somewhat incompetent way.

BROOKE GLADSTONE: There was also, though, the 9/11 Commission Report, which was a bona fide bestseller, and it offered a pretty convincing narrative. Do you think that initially kept the skeptics down?

MARK FENSTER: I think it did, and I think one of the things that the commissioners saw as their role was to not be another Warren Commission; to attempt to write a book that would be popularly available and accessible, that would have a first chapter that would draw readers in, almost like a novel.

BROOKE GLADSTONE: The Warren Commission examined the assassination of JFK and put out an essentially unreadable compendium of documents. You talk about the growth of the conspiracy theorists arising from a backward look of increasing skepticism over the Bush administration and the way they behaved during Katrina and the prosecution of the war and so on. But aren't there certain things that are peculiar to this theory - for instance, the phenomenon of the movie "Loose Change," which may be the most watched online video ever – as many as 10,000,000 viewers, according to Google Video?

MARK FENSTER: The use of visuals and the use of sound in that film is –- I don't want to go so far as to say propagandistic, but it's certainly an extremely persuasive text to those who are willing to watch it with the thought that it might actually be correct.

BROOKE GLADSTONE: Well, what about you? Have you looked at this material carefully and without prejudice, and have you had your doubts?

MARK FENSTER: I'd have to say that the experience of watching "Loose Change" is the experience that I have had reading any or watching any text that alleges a conspiracy. I am someone who enjoys the experience of having the ground move under me as I watch a text like this.

BROOKE GLADSTONE: It sounds like you consume these theories for entertainment.

MARK FENSTER: Well, I think that people do. I mean, I don't want to make light of the idea of conspiracy theory, but lots of things that people find enjoyable allege some kind of conspiracy as the agent that's driving the narrative and that's putting the hero in peril. It is something that drives lots of feature films, lots of popular novels, and I cop to the fact that I enjoy that stuff.

BROOKE GLADSTONE: Well, then, how do you think the press should go about covering this and other conspiracy movements? I mean, covering the 9/11 conspiracists used to consist almost entirely of profiles of seeming whackos, and that's been replaced by profiles of people who are livid at the government but who are otherwise not insane.

MARK FENSTER: [LAUGHS] Right.

BROOKE GLADSTONE: And you've seen increasingly, I mean, this week there was a piece in the AP that took them seriously as people holding this alternative view. How do you think the media should go about putting their arms around this thorny subject?

MARK FENSTER: Well, first and foremost, it's a news event that needs coverage, interviewing not just a leader or a proponent but also someone who has been persuaded. They're providing an important public service because they're covering actual social and political events in that respect. Part of the role of journalism, I think, is to provide sources of information that will counter the allegations made by conspiracy theorists, because if you go online and you Google "9/11 conspiracy," you get thousands of hits at the top of your Google list that allege a conspiracy. It's a lot more difficult to find information that attempts to counter it or respond to it. So I think that's one of the key things that journalists can do.

BROOKE GLADSTONE: All right. Mark, thank you very much.

MARK FENSTER: Thanks for having me.

BROOKE GLADSTONE: Mark Fenster is a law professor at the University of Florida and author of the book Conspiracy Theories: Secrecy and Power in American Culture.