What if I told you I had conclusive proof that the moon landings were faked, but I was coerced into keeping it secret under orders from the CIA, NSA and MI6. Most of you would think I was a loony, but for some, it would seem entirely plausible, or even likely, that an unknown author on an unknown website should stumble over such important information.
We live in a golden age for conspiracy theories and there is a growing assumption that everything we are told by the authorities is wrong, or at the very least, not quite as it seems, and that the truth is being manipulated or obscured by powerful vested interests.
"The reason we have conspiracy theories is that sometimes governments and organisations do conspire," says Observer columnist and academic John Naughton.
It would be wrong to think of all conspiracy theorists as crazy nuts, but for those of us trying to make sense of a complex world, the difficulty is working out which parts of the conspiracy theory to keep and which to throw away.
The internet is generally assumed to be the main driving force behind the growth in modern conspiracy theories, mainly because it gives anyone a voice that can be heard worldwide that they would not have had previously. Also, conspiracy theories were once limited to fringe audiences, and have now become commonplace the mass media.
Mr Naughton is one of three lead investigators in a major new Cambridge University project to investigate the impact of conspiracy theories on democracy. He plans to compare internet theories on 9/11 with pre-internet theories about John F Kennedy's assassination.
Like the other researchers in this field, he is acutely aware of what delving into the darker recesses of the conspiracy world mean.
"The minute you get into the JFK stuff, and the minute you sniff at the 9/11 stuff, you begin to lose the will to live," he told the audience in Cambridge.
Like Sir Richard Evans, who heads the five-year Conspiracy and Democracy project, he is at pains to stress that the aim is not to prove or disprove any particular theories, but to rather study their impact on culture and society. Why are we so fascinated by them? Are they undermining trust in democratic institutions?
David Runciman, professor of politics at Cambridge University, the third principal investigator, is keen to explore the idea that most conspiracies are actually just "cock-ups".
"The line between a cock-up, a conspiracy and a conspiracy theory is much more blurred than the conventional view that you have got to choose between them," he told the Festival of Ideas.
"There's a conventional view that you get these conspirators, who are this kind of sinister, malign people who know what they are doing, and the conspiracy theorists, who occasionally stumble upon the truth but who are on the whole paranoid and crazy.
"Actually the conspirators are often the paranoid and crazy conspiracy theorists because in their attempt to cover up the cock-up they get drawn into the web in which their self-justification poses as some giant conspiracy trying to expose their conspiracy.
"And I think that's consistently true through a lot of political scandals, Watergate included."
It may also be true, he argues, of the in-fighting and plotting that characterised New Labour's years in power, as recently exposed in the memoirs of Gordon Brown's former spin doctor Damian McBride.
The Brownite conspiracies to remove Tony Blair were "pathetically ineffectual" - with the exception of the 2006 "curry house" plot that forced Blair to name a departure date - but the picture painted by Mr McBride of a "paranoid" and "chaotic" inner circle has the ring of truth about it, he claims, and Mr Brown - said to be a keen student of the JFK assassination - knew a conspiracy when he saw one.
"You feel he sees conspiracies out there because he has a mindset that is not dissimilar to the conspiracy theorists," said Prof Runciman.
He is also examining whether the push for greater openness and transparency in public life will fuel, rather than kill off, conspiracy theories.
"It may be that one of the things conspiracy theories feed on as well as silence, is a surfeit of information. And when there is a mass of information out there, it becomes easier for people to find their way through to come to the conclusion they want to come to.
"Plus, you don't have to be an especial cynic to believe that, in the age of open government, governments will be even more careful to keep secret the things they want to keep secret.
"The demand for openness always produces, as well as more openness, more secrecy."