As shown above, the US authorities have failed to prove that the 19 individuals accused of the mass murder of 9/11 had boarded the aircraft, which they allegedly used to commit the crime. No authenticated, original, passenger lists, bearing their names, have been released; no one is known to have seen them board the aircraft; no video recordings documented their boarding; no boarding pass stub is known to exist; and there is no actual proof that the alleged hijackers actually died at the known crash sites, because their bodily remains were not positively identified (except for one dubious case) and no chain-of-custody report accompanied these remains.
In the months following 9/11, reports appeared in mainstream media that at least five of the alleged hijackers were actually living in various Arab countries.  These reports led to speculation that the identities of some of the hijackers were in doubt. Typical of such reports is an Associated Press dispatch of 3 November 2001, which states: "The FBI released the names and photos of the hijackers in late September. The names were those listed on the planes' passenger manifests and investigators were certain those were the names the hijackers used when they entered the United States. But questions remained about whether they were the hijackers' true identities. The FBI has not disclosed which names were in doubt and [FBI Director] Mueller provided no new information on the hijackers' identities beyond his statement to reporters." The 9/11 Commission did neither address at all these doubts nor the reports about the "living hijackers".
On September 14, 2001, the FBI released the names of the 19 individuals "who have been identified as hijackers aboard the four airliners that crashed on September 11, 2001".  On September 27, 2001, the FBI released photographs of these 19 individuals. Withdrawing from its unqualified statement of September 14, the new press release said these were photographs the FBI merely "believed to be the hijackers of the four airliners".  Yet for most names no birth date, birthplace or specific residence is given despite the apparent availability of such data on visa application forms and other documentation possessed by the FBI. The FBI webpage provides the following caveat: "It should be noted that attempts to confirm the true identities of these individuals are still under way." This statement, issued on September 27, 2001, is still valid today, anno 2008, because the webpage has not been updated since it was initially posted and remains, therefore, the US government's official position that their identities are in doubt. Accordingly, a significant difference exists between the official position of the US government, as reflected by the website of the FBI, regarding the identities of the alleged perpetrators of the crime committed on 9/11 and the popularized version parroted by politicians and the media about the guilt of 19 Muslims for the mass murder of 9/11. The 9/11 Commission has studiously avoided the question of the alleged hijackers' identities. It must be added, however, that the aforementioned statement is deliberately deceptive, because there is no hard evidence that any person actually hijacked the airliners and crashed them on the known sites.
Not everyone is convinced that the above account disposes of the question whether or not Muslim fanatics hijacked planes on 9/11. Some people claim that callers from the aircraft actually described the hijackers as Arabs and even mentioned their seat numbers. Such electronically transmitted evidence would have strengthened the official allegations if it had been supported by solid primary evidence, namely that these "hijackers" had actually boarded these aircraft and died at the known crash sites. Absent this primary evidence such secondary evidence cannot be considered as the proof for the presence of these "hijackers" on the aircraft. Additionally, numerous questions remain unanswered regarding the location from which the phone calls were made and their authenticity. 
Another recurring counter-argument is that a man claiming to be the notorious terrorist Khaled Sheikh Mohammed, reportedly detained at the GuantanÃ¡mo base, had confessed to be the mastermind of the 9/11 attacks. Here again, in the absence of primary evidence proving that the 19 "hijackers" actually boarded the aircraft which they hijacked and crashed, such claims by someone whose identity is shrounded in mystery and who was no eyewitness to the events of 9/11 cannot supplant primary evidence.
More than seven years have elapsed since the events of 9/11. The U.S. government had in those years sufficient time to prove the identities of the persons who allegedly boarded and crashed airplanes on 9/11, if any. If the official account on 9/11 were true, the U.S. government, more than anyone else, would have trumpeted this evidence in order to prove to the world, once and for all, who committed the crime. No one would have benefitted more from publicizing such evidence than the U.S. government.
While it is theoretically possible that the U.S. government possesses the evidence that would prove its accusations against the 19 named "hijackers", such possibility becomes less and less plausible as time passes. The total absence of evidence proving the guilt of Muslims for the crime of 9/11 gives rise to the following observations:
(a) Due to the lack of evidence regarding the guilt of the 19 named Muslims for the crime of 9/11, it is unconscionable to claim that Muslims (or al Qaeda) committed this crime. Any such accusations or insinuations amount to slander and possibly racial incitement.
(b) In view of harmful policies pursued by the U.S. government on the base of allegedly secret evidence, it is politically irresponsible to accord the US Government the benefit of the doubt by presuming the existence, albeit hidden, of incriminating evidence against Muslims for the crime of 9/11.
(c) The lack of evidence regarding the boarding of the four airliners that reportedly crashed on 9/11 and the failure of the U.S. government to formally prove its case, justify suspicion about its complicity in the crime of 9/11 and its cover-up.
The crime of 9/11 has served to justify two wars of aggression by the United States, an indefinite and global "war on terror", the imposition of the PATRIOT Act, spying of the public, and serious violations of international law. Many governments have colluded in these violations and endorsed U.S. lies regarding the events of 9/11. The continuous reliance on the official account regarding 9/11 therefore threatens international peace and security. The above account should therefore prompt all those who are concerned by human rights violations and the threat to international peace and security, to join in demanding the full truth on the events of 9/11.
Elias Davidsson's website is http://www.juscogens.org