The Guardian: A 9/11 conspiracy virus is sweeping the world, but it has no basis in fact
George Monbiot takes apart the 9/11 conspiracy film Loose Change, which advances the well-known "no plane" theory:
The only people they interview are a janitor, a group of firemen, and a flight instructor. They let the janitor speak at length, but cut the firemen off in mid-sentence. The flight instructor speaks in short clips, which give the impression that his pupil, the hijacker Hani Hanjour, was incapable of hitting the Pentagon. Elsewhere he has said the opposite: he had "no doubt" that Hanjour could have done it.
Where are the structural engineers, the materials scientists, the specialists in ballistics, explosives or fire? The film-makers now say that the third edition of the film will be fact-checked by an expert, but he turns out to be "a theology professor". They don't name him, but I would bet that it's David Ray Griffin, who also happens to be the high priest of the 9/11 conspiracists.
The next evident flaw is that the plot they propose must have involved tens of thousands of people. It could not have been executed without the help of demolition experts, the security firms guarding the World Trade Centre, Mayor Giuliani (who hastily disposed of the remains), much of the US air force, the Federal Aviation Administration and the North American Aerospace Defence Command, the relatives of the people "killed" in the plane crashes, the rest of the Pentagon's staff, the Los Alamos laboratories, the FBI, the CIA, and the investigators who picked through the rubble.
Monbiot notes that Counterpunch commissioned an expert of their own to investigate the National Institute of Science and Technology report into the failure of the Twin Towers to withstand the hit; you can find the articles here along with Alexander Cockburn's own attack on the theories. Monbiot concludes that if the theories had any substance, those proposing them would have been assassinated years ago if the US government was "running an all-knowing, all-encompassing conspiracy".

We ought to keep a critical mind and examine all voices on the tragedy:
http://www.guardian.co.uk/letters/story/0,,2007936,00.html
Unless of course you still firmly believe that the comintern set fire to the Reichstag, Oswald alone killed Kennedy, a lone NOI member martyred Malik Shabazz and that the Volgodonsk apartments were destroyed by Chechens.
In response to Haroon's comment:
Keeping a critical mind means that you don't lump all those events together: In my opinion, the truth about them probably runs: false, true, false false.
Having looked into 9/11 a bit, it seems amazing that anyone can disregard all the weight of evidence that it really was a conspiracy of radical, mostly Saudi, islamists aiming to kill as many people as possible by flying planes into buildings. All the rest - controlled explosions, missiles, passengers impersonated then disposed of etc, is just too complex to have been got away with. Look at the last example you give, the Ryazan apartment bombs. All the FSB had to do was plant a few bombs late at night in undefended apartment blocks - and they still got caught doing it. The whole 9/11 "conspiracy" would have taken thousands of people, some really advanced technology and utter secrecy. It didn't happen that way.
Occam's razor's a very useful tool - the simplest explanation in keeping with the known facts is probably the right one.
I think you should consider carefully why you want that to be true and why so many other muslims in Britain believe it to be so.
The 9/11 denial movement began alsmost as soon as the towers fell. Within a couple of days, a muslim colleague passed me a tract he'd been given at the mosque. To summarise: "Who could have done such a terrible thing? The one people wicked enough - the jews!"
I do wonder if people really, really believe these things. If they did, surely it would be impossible to exist within such a homicidal society.
If the beliefs are merely just a retreat from reason and grown-up thinking into fantasy, then they serve a purpose, albeit a rather unpleasant one.
Thanks for that Simon. But do remember we were dealing with that rare brand of Saudi Islamists who apparently got stoned and cavorted with whores the night before their "martyrdom". Im of the opinion that elements within the US administration knew what was going to happen and allowed events to proceed anyway. Whether this automatically consigns me to that sad portion of humanity who believes that Elvis works at their local branch of Wal-Mart remains to be seen. In any case, the architects of PNAC got their "catastrophic and catalysing Pearl Harbour event". The rest is history.