I was thinking about this in the car earlier. There seems to be 4 different type of people when it comes to conspiracies:

1. People who believe in conspiracies
2. Haters (know about conspiracies and actively try to debunk them)
3. Knowledgable people (know about conspiracies but don't believe them)
4. Ignorant people (don't know about conspiracies and don't reject them)

With enough evidence and information, it's possible to educate groups #3 and #4.

Group #4 is the easiest because they know nothing. If you start to introduce some topics and provide evidence they will start to investigate on their own and maybe turn into conspiracy believers themselves.

The knowledgable people (group #3) are a bit harder to convince. They've maybe heard things from friends or read some sketchy info on the Internet. They don't believe because they have limited or bad information. If you can connect them to the right sources and provide facts and evidence you can start to turn them around. With enough discussion you might even win them over and open their eyes.

But, group #2 is the hardest. These people actively resist learning the truth. They go out of their way to make up evidence to "debunk" conspiracies. They try to convince people in groups #3 and #4 to not even listen. They engage in name calling and ad hominem attacks. They present a bunch of logical fallacies to try to convince themselves (and others) that the evidence for conspiracies are false.

Why? They are seemingly intelligent people otherwise. If you presented them with compelling evidence that their landlord was cheating them they'd believe it. If you showed them evidence that the fuel they were using in their car was reducing performance and costing money they'd study it.... and probably believe. They are able to follow the scientific method when it comes to other facts and evidence in their lives. So, why do they insist on rejecting the evidence when it comes to conspiracies?

In the case of 9/11 there were thousands of experts that came forward with evidence (police, firefighters, pilots, architects, engineers, etc.) So, why won't group #2 listen to or study the evidence? The sources are legitimate. The evidence is accurate and has been peer-reviewed.

I think the answer is that it destroys their world view. Like the saying goes: "ignorance is bliss". If your whole world view is set up to reinforce the fiction that everything is OK and that things will somehow work out, conspiracy theories are quite destructive. Once your eyes are open --and you learn the truth-- you can never go back to viewing the world the way that you used to. Everything changes.

This is what the idiots over at conspiritard are most afraid of. It's what the 9/11 and Sandy Hook debunkers are afraid of. They have built up a nice little model of how the world is... and things are looking up. They can go on living their lives thinking that things will get better soon. The future is full of hope and potential!

Conspiracy theories burst this bubble. They cause the wave of optimistic superposition to collapse. It's hard to be happy when you realize that you're a slave in a system built entirely on control and manipulation. This is what they are fighting against. It's not that they disagree with the particular conspiracy that your'e discussing -- it's the idea of ALL conspiracy theories. If they study the facts and learn the truth it means that part of their world will collapse. The more they learn, the more their fictional dream world is destroyed. They can't allow this to happen!

This is why you see massive downvote brigades and haters crawling out of the woodwork to attack conspiracy forums and believers. This is why they spam and troll. This is why they post disinformation and lies. This is why they seek out conspiracy forums and go out of their way to cause trouble. It's all about protecting their fragile world view. If they can just make conspiracy go away then everything will be fine again. The problem will go away. It's a way to protect themselves from the truth.