9/11, Death Of Marilyn Monroe, JFK, Princess Diana, Was it a conspiracy or is...

A variety of conspiracy theories question the mainstream account of the September 11, 2001 attacks in the United States. Since the September 11, 2001 attacks, a number of theories challenging the mainstream account of the attacks have been put forward in websites, books, and films. Immediately following the September 11, 2001 attacks, the U.S. government stated that nineteen terrorists hijacked four commercial airplanes by using knives, box cutters, pepper spray, and fake explosives. Most 9/11 conspiracy theories generally originate from dissatisfaction with the mainstream account of 9/11. The issue of whether anyone outside al-Qaeda was aware that the attacks were going to take place has been a subject of some theories. Many 9/11 theories claiming government involvement allege that the US air defense system, NORAD, was deliberately stood down or rendered ineffective.