Finally! They admit it! Conspiracies aren't theories- a theory is a broad explanation of how independent facts fit into a cohesive whole, similar to a jigsaw puzzle. Theories are rigorously tested and individual puzzle pieces may be moved around, but if the image garnered from the puzzle is still the same, the theory has been proven.
A conspiracy, on the other hand, is more closely related to a religion. There are believers, there are "sheeple", and there are "Them". Conspiracies fall apart under even the most light logical and/or factual scrutiny, therefore they prey on people's fears, emotions and paranoia, "anchoring" themselves to the person's opinions and worldview, which are much harder to question. For example, if someone is deeply cynical of the Government, they will fall back on that belief as their conspiracy comes under attack, thereby rendering arguments against the conspiracy useless. It is a insidious system but remarkably easy to predict once you get the hang of it. A conversation may go like this:
'no it didn't, for reasons Y.'
"But group Z would do something like that! Do you really think that group Z wasn't involved? They're evil. Of course they did X."
'you're letting your mistrust of Z cloud your judgement. Evil or not, Z did not do X.'