Conspiracy theories can be broadly classified into event conspiracies, systemic conspiracies, and super conspiracies. Event conspiracies are those that focus around a single event, such as the assassination of John F. Kennedy, or the terrorist attacks of 9/11. Systemic conspiracies are those that involve complex systems over a long period of time, such as water fluoridation, or the establishment of a dictatorial World Government by some elite group. Super conspiracies consist of multiple separate conspiracies spanning the entire spectrum of subjects, all linked together into one overarching master plan.
The conspiracy theory type that occurs in the largest numbers is the Event Conspiracy. Event conspiracies now spring up almost immediately after the event, even for seemingly mundane happenings. When the lights when out in the stadium at the 2013 Superbowl, there were almost immediate suggestions that it was done deliberately, perhaps by some shadowy hacker group such as Anonymous, in order to give the trailing 49ers a chance to regroup. This was probably reinforced in the minds of the suspicious when the 49ers managed to rally in the second half, almost defeating the Ravens.
Much more disturbingly, event conspiracy theories sprang up immediately after the shootings of twenty children and six adults at the Sandy Hook Elementary School in Newton Connecticut. A huge range of conspiracies were concocted. Most event conspiracy theories fall loosely into one of four sub-types, in increasing order of improbability:
Exploited Event - the “Glad it happened” theory. Here the events are genuine, and the conspirers are as surprised as anyone that they happened - however they immediately begin to exploit those events, and spin, lie, and distort what actually happened to further their goals. Here 9/11 was framed in such a way that many people got the impression that Saddam Hussein was responsible for the attacks, and this was used to provide justification for the Iraq War. The Sandy Hook shootings were misreported and exploited in order to take away peoples guns.
Allowed Event - the “Let it happen” theory. Here the events are as they appeared to be. The 9/11 attacks were performed by terrorists hijacking planes. JFK was shot by Lee Harvey Oswald. However in this scenario, there is a set of secret conspirers (usually people in power, such as the executive branch of the government, or elements of government agencies) who are aware of the planned event ahead of time, and they could have stopped it by warning people. But they keep silent, and let the event happen because it benefits them in some way. Here George W. Bush allowed the attacks on 9/11 because they would provide justification for invading Iraq. Here the attacks on Pearl Harbor were known days in advance by the US and/or British government, but they let it happen to provide popular support for the US entering the Second World War.
Deliberate Event - the “Made it happen” theory. Here the events are real, but they were performed or ordered by the people behind the conspiracy. In this scenario the World Trade Center was hit by remote control planes, and the buildings brought down by controlled demolition. JFK was shot by a CIA sniper. The Sandy Hook children were shot by gunmen dressed as nuns who dumped Adam Lanza’s drugged and shot body after they had slaughtered the innocents.
Faked Event - the “It didn’t happen” theory. Here the entire event is a concoction of the government and the media. In this world view, we are living in a “matrix” style constructed reality. This is not to say we are living in a computer simulation, but that nearly everything portrayed in the media is faked. Nobody landed on the Moon, no planes struck the World Trade Center, no children were killed at Sandy Hook. They were all somehow staged to provide justification for some action. The 9/11 planes were computer animated, the videos are all faked, the people running in the street were all actors.
While you can usually describe any particular conspiracy theory by labeling it as one of the above four types of event, it’s quite rare that it fits neatly within a single category. In particular the exploitation of an event is presumed to be happening regardless of the event was allowed, deliberate, or (especially) faked. Some events are supposedly half-way between “Allowed” and “Deliberate”, perhaps Adam Lanza was known to be a psychopath with access to guns, and was given drugs that made him violent, or perhaps he was brainwashed by voices beamed into his head at night. A kind of “helped it happen” theory.
It’s important when debunking to be clear which particular type of conspiracy you are dealing with. Many, if not most people would agree that people within the Bush administration exploited the events of 9/11. Fewer, but still a significant number, think that Bush had some kind of foreknowledge of some kind of attack, at least to the extent of not fully acting on warnings. Fewer still think that Bush knew specifically what the attacks would be. A very small percentage of people think that Bush and others in power deliberately engineered the attacks using the terrorists. An even smaller percentage thinks that the attacks happened, but not with terrorists, but with remote control planes, and deliberate controlled demolition. Hardly anyone think that the attacks did not happen at all, and were entirely faked.
And yet the people who promote the more exotic conspiracy theories (like controlled demolition of the World Trade Center) will often use the number of people who suspect the more mundane (like Bush exploiting the events to invade Iraq) to bolster their case. They will take the fact that a large number of people are naturally suspicious of the actions of the Government relating to 9/11 and try to hijack those numbers to suggest that their own bizarre theory of controlled demolition has broad popular support. But while many people would sign a petition that called for a new and open investigation of the events of 9/11, not all, and probably not even a significant fraction of them, strongly believe that the building were deliberate destroyed by Bush administration operatives with explosives.