9/11 was the first global event in the age of the internet. And now the world wide web is being used as a platform for a wide range of conspiracy theories ... which allege that the US government was somehow involved in the attacks. Those who question the official account of 9/11 form a broad coalition. Loose Change has been viewed tens of millions of times and pulls no punches. [Creator Dylan Avery claims] "our government will willingly kill its own citizens for whatever gain it deems necessary ... and then lie as much as they need to cover it up." At the other extreme [Professor Jim] Fetzer is a former US Marine officer and retired professor of philosophy. Puzzled by the apparent discrepancies in the official account of 9/11, he founded a coalition of like-minded academics called Scholars For 9/11 Truth. Its purpose is to research exactly what happened that day, using the principles of scientific research. Alex Jones, a nationally syndicated radio talk show host ... believes 9/11 was "an inside job." "It's a self inflicted wound, it's a false-flag terror operation," he claims. After the attacks, government officials were summoned to give evidence before a Congressional Inquiry set up to investigate the intelligence failure before 9/11. Co-chairman Senator Bob Graham told ... of his frustration at the lack of co-operation from the FBI in that inquiry, and by the government's decision to censor over 30 pages of his report which related to Saudi Arabia. "Within 9/11 there are too many secrets," he said, "withholding of those secrets has eroded public confidence in their government."