Those who would assert that Osama bin Laden did 9/11 must still account for the physical evidence: 3 buildings in New York destroyed with 2 planes, the freefall of WTC 7 with simultaneous onset across the whole building, the uniform downward acceleration of the Twin Towers (which can be accounted for by demolition and nothing else that has been proposed), the excess energy of the destruction at the WTC over and above the potential energy of the buildings, the impossibility that the planes actually caused the collapses an hour or more later, the existence of unreacted nanothermite flakes in the WTC dust, etc. How is the supposed letter of a known CIA asset to be considered more reliable than physical evidence?