The following is from 911truth.org, extra info and back-up for the claims made have been added in the form of hyperlinks and bracketed text.
THE TOP 40 REASONS TO DOUBT THE OFFICIAL STORY OF SEPTEMBER 11th, 2001
THE DAY ITSELF - EVIDENCE OF COMPLICITY
1) AWOL Chain of Command
b. Who was actually in charge? Dick Cheney, Richard Clarke, Norman Mineta and the 9/11 Commission directly conflict in their accounts of top-level response to the unfolding events, such that several (or all) of them must be lying.
2) Air Defense Failures
a. The US air defense system failed to follow standard procedures for responding to diverted passenger flights.
3) Pentagon Strike
5) Flight 93
THE DAY - POSSIBLE SMOKING GUNS
6) Did cell phones work at 30,000 feet in 2001? How many hijackings were attempted? How many flights were diverted?
7) Demolition Hypothesis
What caused the collapse of a third skyscraper, WTC 7, which was not hit by a plane? Were the Twin Towers and WTC 7 brought down by explosives? (See "The Case for Demolitions," the websites wtc7.net and 911research.wtc7.net, and the influential article by physicist Steven Jones. See also items no. 16 and 24, below.)
FOREKNOWLEDGE & THE ALLEGED HIJACKERS
8) What did officials know? How did they know it?
a. Multiple allied foreign agencies informed the US government of a coming attack in detail, including the manner and likely targets of the attack, the name of the operation (the "Big Wedding"), and the names of certain men later identified as being among the perpetrators.
9) Able Danger, Plus - Surveillance of Alleged Hijackers
a. The men identified as the 9/11 ringleaders were under surveillance for years beforehand, on the suspicion they were terrorists, by a variety of US and allied authorities - including the CIA, the US military''s "Able Danger" program, the German authorities, Israeli intelligence and others.
10) Obstruction of FBI Investigations prior to 9/11
A group of FBI officials in New York systematically suppressed field investigations of potential terrorists that might have uncovered the alleged hijackers - as the Moussaoui case once again showed. The stories of Sibel Edmonds, Robert Wright, Coleen Rowley and Harry Samit, the "Phoenix Memo," David Schippers, the 199i orders restricting investigations, the Bush administration's order to back off the Bin Ladin family, the reaction to the "Bojinka" plot, and John O'Neil do not, when considered in sum, indicate mere incompetence, but high-level corruption and protection of criminal networks, including the network of the alleged 9/11 conspirators. (Nearly all of these examples were omitted from or relegated to fleeting footnotes in The 9/11 Commission Report.)
11) Insider Trading
a. Unknown speculators allegedly used foreknowledge of the Sept. 11th events to profiteer on many markets internationally - including but not limited to "put options" placed to short-sell the two airlines, WTC tenants, and WTC re-insurance companies in Chicago and London.
[Counter point: More on the 9/11 Put Options]
12) Who were the perpetrators?
b. The identities of the alleged hijackers remain unresolved, there are contradictions in official accounts of their actions and travels, and there is evidence several of them had "doubles," all of which is omitted from official investigations.
c. What happened to initial claims by the government that 50 people involved in the attacks had been identified, including the 19 alleged hijackers, with 10 still at large (suggesting that 20 had been apprehended)? http://www.chicagotribune.com/news/nationworld/sns-worldtrade-50suspects,0,1825231.story
THE 9/11 COVER-UP, 2001-2006
[In 2001 then Secretary of State Colin Powell stated that the government would soon "put out a paper ... that will describe clearly the evidence that we have linking" bin Laden to 9/11. One day later the government reneged on this pledge and no such paper has ever been offered. So it seems that the first statement from the FBI was the honest one. Bin Laden has admitted to being involved in 9/11, but just like the FBI he has made contraduictory statements and denied his guilt on three reported occasions, including once on video, but this doesn't mean he wasn't involved. Afterall, there is circumstantial evidence against him in the form of a video showing him meeting with with some of the hijackers. And as 911myths.com points out, "Since 9/11, al-Qaeda have released footage of several of the hijackers. These include a number of video wills, where they talk about jihad and attacking America." Click here for more info.]
b. Did Osama Bin Ladin visit Dubai and meet a CIA agent in July 2001 (Le Figaro)? Was he receiving dialysis in a Pakistani military hospital on the night of September 10, 2001 (CBS)?
c. Whether by Bush or Clinton: Why is Osama always allowed to escape?
d. The terror network associated with Osama, known as the "data base" (al-Qaeda), originated in the CIA-sponsored 1980s anti-Soviet jihad in Afghanistan. When did this network stop serving as an asset to covert operations by US intelligence and allied agencies? What were its operatives doing in Kosovo, Bosnia and Chechnya in the years prior to 9/11?
14) All the Signs of a Systematic 9/11 Cover-up
a. Airplane black boxes were found at Ground Zero, according to two first responders and an unnamed NTSB official, but they were "disappeared" and their existence is denied in The 9/11 Commission Report.
15) Poisoning New York
The White House deliberately pressured the EPA into giving false public assurances that the toxic air at Ground Zero was safe to breathe. This knowingly contributed to an as-yet unknown number of health cases and fatalities, and demonstrates that the administration does consider the lives of American citizens to be expendable on behalf of certain interests.
16) Disposing of the Crime Scene
The rapid and illegal scrapping of the WTC ruins at Ground Zero disposed of almost all of the structural steel indispensable to any investigation of the collapse mechanics. (See also item no. 23, below.)
Mailings of weapons-grade anthrax - which caused a practical suspension of the 9/11 investigations - were traced back to US military stock. Soon after the attacks began in October 2001, the FBI approved the destruction of the original samples of the Ames strain, disposing of perhaps the most important evidence in identifying the source of the pathogens used in the mailings. Were the anthrax attacks timed to coincide with the Afghanistan invasion? Why were the letters sent only to media figures and to the leaders of the opposition in the Senate (who had just raised objections to the USA PATRIOT Act)?
18) The Stonewall
a. Colin Powell promised a "white paper" from the State Department to establish the authorship of the attacks by al-Qaeda. This was never forthcoming, and was instead replaced by a paper from Tony Blair, which presented only circumstantial evidence, with very few points actually relating to September 11th.
19) A Record of Official Lies
a. "No one could have imagined planes into buildings" - a transparent falsehood upheld repeatedly by Rice, Rumsfeld and Bush.
20) Pakistani Connection - Congressional Connection (FBI Whistleblower Exposes New Dimensions To 'Pakistan Connection')
a. The Pakistani intelligence agency ISI, creator of the Taliban and close ally to both the CIA and "al-Qaeda," allegedly wired $100,000 to Mohamed Atta just prior to September 11th, reportedly through the ISI asset Omar Saeed Sheikh (later arrested for the killing of Wall Street Journal reporter Daniel Pearl, who was investigating ISI connections to "al-Qaeda.")
["9/11 Myths" Takes on Pakistan's ISI Link to 9/11 Funding]
21) Unanswered Questions and the "Final Fraud" of the 9/11 Commission:
a. The September 11th families who fought for and gained an independent investigation (the 9/11 Commission) posed 400-plus questions, which the 9/11 Commission adopted as its roadmap. The vast majority of these questions were completely ignored in the Commission hearings and the final report.
22) Crown Witnesses Held at Undisclosed Locations
The alleged masterminds of 9/11, Khalid Sheikh Mohamed (KSM) and Ramzi Binalshibh, are reported to have been captured in 2002 and 2003, although one Pakistani newspaper said KSM was killed in an attempted capture. They have been held at undisclosed locations and their supposed testimonies, as provided in transcript form by the government, form much of the basis for The 9/11 Commission Report (although the Commission''s request to see them in person was denied). After holding them for years, why doesn''t the government produce these men and put them to trial?
23) Spitzer Redux
a. Eliot Spitzer, attorney general of New York State, snubbed pleas by New York citizens to open 9/11 as a criminal case (Justicefor911.org).
24) NIST Omissions
After the destruction of the WTC structural steel, the official Twin Towers collapse investigation was left with almost no forensic evidence, and thus could only provide dubious computer models of ultimately unprovable hypotheses. It failed to even test for the possibility of explosives. (Why not clear this up?)
25) Radio Silence
The 9/11 Commission and NIST both allowed the continuing cover-up of how Motorola''s faulty radios, purchased by the Giuliani administration, caused firefighter deaths at the WTC - once again showing the expendability, even of the first responders.
26) The Legal Catch-22
a. Hush Money - Accepting victims'' compensation barred September 11th families from pursuing discovery through litigation.
27) Saudi Connections
a. The 9/11 investigations made light of the "Bin Ladin Airlift" during the no-fly period, and ignored the long-standing Bush family business ties to the Bin Ladin family fortune. (A company in which both families held interests, the Carlyle Group, was holding its annual meeting on September 11th, with George Bush Sr., James Baker, and two brothers of Osama Bin Ladin in attendance.)
28) Media Blackout of Prominent Doubters
The official story has been questioned and many of the above points were raised by members of the US Congress, retired high-ranking officers of the US military, the three leading third-party candidates for President in the 2004 election, a member of the 9/11 Commission who resigned in protest, a former high-ranking adviser to the George W. Bush administration, former ministers to the German, British and Canadian governments, the commander-in-chief of the Russian air force, 100 luminaries who signed the "9/11 Truth Statement," and the presidents of Iran and Venezuela. Not all of these people agree fully with each other, but all would normally be considered newsworthy. Why has the corporate-owned US mass media remained silent about these statements, granting due coverage only to the comments of actor Charlie Sheen?
GEOPOLITICS, TIMING AND POSSIBLE MOTIVES
29) "The Great Game"
The Afghanistan invasion was ready for Bush''s go-ahead on September 9, 2001, with US and UK force deployments to the region already in place or underway. This followed the failure earlier that year of backdoor diplomacy with the Taliban (including payments of $125 million in US government aid to Afghanistan), in an attempt to secure a unity government for that country as a prerequisite to a Central Asian pipeline deal.
30) The Need for a "New Pearl Harbor"
Principals in US foreign policy under the current Bush administration (including Cheney, Rumsfeld, Wolfowitz, Perle and others) have been instrumental in developing long-running plans for worldwide military hegemony, including an invasion of the Middle East, dating back to the Ford, Reagan and Bush Sr. administrations. They reiterated these plans in the late 1990s as members of the "Project for a New American Century," and stated a clear intent to invade Iraq for the purpose of "regime change." After 9/11, they lost no time in their attempt to tie Iraq to the attacks.
31) Perpetual "War on Terror"
9/11 is supposed to provide carte-blanche for an open-ended, global and perpetual "War on Terror," against any enemy, foreign or domestic, that the executive branch chooses to designate, and regardless of whether evidence exists to actually connect these enemies to 9/11.
32) Attacking the Constitution
a. The USA PATRIOT Act was written before 9/11, Homeland Security and the "Shadow Government" were developed long before 9/11, and plans for rounding up dissidents as a means for suppressing civil disturbance have been in the works for decades.
b. 9/11 was used as the pretext to create a new, extra-constitutional executive authority to declare anyone an "enemy combatant" (including American citizens), to detain persons indefinitely without habeas corpus, and to "render" such persons to secret prisons where torture is practiced.
33) Legal Trillions
9/11 triggers a predictable shift of public spending to war, and boosts public and private spending in the "new" New Economy of "Homeland Security," biometrics, universal surveillance, prisons, civil defense (http://en.wikipedia.org/wiki/Civil_defense), secured enclaves, security, etc.
34) Plundered Trillions?
On September 10, 2001, Donald Rumsfeld announced a "war on waste" after an internal audit found that the Pentagon was "missing" 2.3 trillion dollars in unaccounted assets. On September 11th, this was as good as forgotten.
35) Did 9/11 prevent a stock market crash?
Did anyone benefit from the destruction of the Securities and Exchange Commission offices at WTC 7, and the resultant crippling of hundreds of fraud investigations?
36) Resource Wars
a. What was discussed in the Energy Task Force meetings under Dick Cheney in 2001? Why is the documentation of these meetings still being suppressed?
b. Is Peak Oil a motive for 9/11 as inside job?
37) The "Little Game"
Why was the WTC privatized just before its destruction?
The longstanding relationship between US intelligence networks and radical Islamists, including the network surrounding Osama Bin Ladin. (See also point 13d.)
39) Historical Precedents for "Synthetic Terror"
a. In the past many states, including the US government, have sponsored attacks on their own people, fabricated the "cause for war," created (and armed) their own enemies of convenience, and sacrificed their own citizens for "reasons of state."
b. Was 9/11 an update of the Pentagon-approved "Project Northwoods" plan for conducting self-inflicted, false-flag terror attacks in the United States, and blaming them on a foreign enemy?
40) Secret Government
a. The record of criminality and sponsorship of coups around the world by the covert networks based within the US intelligence complex.
b. Specifically also: The evidence of crime by Bush administration principals and their associates, from October Surprise to Iran-Contra and the S&L plunder to PNAC, Enron/Halliburton and beyond.
REASON NUMBER 41:
RELATED MOVEMENTS AND PARALLEL ISSUES
Ground Zero aftermath movements: - Justice for the air-poisoning cover-up (wtceo.org)- "Radio Silence" (radiosilencefdny.com)- Skyscraper Safety (http://www.skyscrapersafety.org/).
Election fraud and black box voting, 2000 to 2004. (BlackBoxVoting.org)
Lies to justify the invasion of Iraq. (afterdowningstreet.org)
Use of depleted uranium and its multi-generational consequences on human health and the environment.
Longstanding development of contingency plans for civil disturbance and military rule in the USA (See, "The War at Home")
Oklahoma City Truth movement. (Offline, but not forgotten - May 9, 2008!)
Whether you call it "Globalization" or "The New World Order" - An unsustainable system of permanent growth ultimately requires warfare, fraud, and mass manipulation.
GOING FORWARD ..."But an inside job would involve thousands of people! How could they keep a secret?" Counter-arguments, red herrings, speculations and false information.
Selected essays, books and websites that make the case for 9/11 as inside job. (See Resources)
Demanding a real investigation of the September crimes - Not just a patriotic duty, but a matter of survival. (End of 911truth.org article.)
Still not convinced that the facts speak for themselves? Perhaps you are a coincidence theorist, or GASP... a 9/11 debunker!