First is the notion that Osama Bin Laden and al-Qaeda were responsible for 9/11. Al-Qaeda did not exist in name until 9/11. Al-Qaeda literally means the database and refers to the list of Mujahideen fighters trained by the CIA to resist the Russian occupation of Afghanistan. Sibel Edmonds, a former FBI translator, was able to circumvent the gag-order imposed upon her to testify that the US had worked intimately with the Taliban and Bin Laden right up until 9/11. Note also that Bin laden is not wanted by the FBI in conjunction with 9/11. When asked why, Rex Tomb, Chief of Investigative Publicity for the FBI, stated that there was "no hard evidence connecting Bin Laden to 9/11".
Finally, many people do not know that three buildings actually came down in New York on 9/11. WTC 7 was a 47 story building that was not hit by a plane and fell symmetrically at near free-fall into its own footprint. In fact, NIST was forced to admit that WTC 7 fell for 2.25 seconds at total free fall. This means the massive steel support columns of this building were somehow all blown out simultaneously and continuously for that period to ensure there was no structural resistance whatsoever to the falling building. There is no way on Earth that office fires can do something like this. Explosives can do this, which is why explosives, and not fires, are used in the controlled demolition of buildings.
Do you remember your high school physics? When a moving car hits a stationary car, does the moving car go through the other car or do both cars travel at the same velocity as the first? No. Cars, like everything else on Earth, follow the laws of physics. Some of the momentum and kinetic energy of the first car is transferred to the other car; some is converted to heat due to friction; and some is used up in the deformation of both cars as per conservation laws. In a closed system you can't magically add energy to or remove energy from the system. All the available energy and momentum must balance. Since all the energy and momentum of WTC 7 during those 2.25 seconds was used in gravitationally accelerating downward, there was nothing left to completely remove the considerable support structure that held this massive building up for all those years. Some enormous amount of energy had to be added to this system to remove the structure. In controlled demolitions this extra energy comes from explosives. So the official story of how WTC 7 fell does not conserve energy or momentum, violating the laws of physics and is therefore false.
Now you might be thinking "OK it seems as if WTC 7 was brought down with explosives, but al-Qaeda still could have rigged this". However, WTC 7 was one of the most secure buildings on Earth housing offices of the CIA, US secret service, the IRS, the SEC and the Mayor's Office of Emergency Management. How could al-Qaeda operatives plant explosives in such a highly secure building?
The official conspiracy theory of 9/11 is based on a serious of lies. I have merely pointed out some of the most egregious. This means all the events resulting from 9/11 including the invasion of three countries (Afghanistan, Iraq and Pakistan), torture, untold civilian deaths and the steady erosion of personal liberties are all based on lies. Logically, there is nothing wrong with entertaining a conspiracy theory provided it best explains the available facts. However, when a conspiracy theory violates the laws of physics, it enters the realm of the unhinged crackpot. I leave you with the words of the great H.L. Mencken: "The whole aim of practical politics is to keep the populace alarmed, and hence clamorous to be led to safety, by menacing it with an endless series of hobgoblins, all of them imaginary."
 The Guardian, 8 July 2005, "The Struggle Against Terrorism Cannot Be Won by Military Means," Robin Cook, click here
 click here:-Bin-Laden-worked-for-US-till-9-11
 The Muckraker Report, June 6, 2006, and Ithaca Journal, June 29, 2006
 NIST NCSTAR 1A http://wtc.nist.gov/NCSTAR1/PDF/NCSTAR%201A.pdf
 New York Times, November 4, 2001 in the click here
 click here