Very rarely do I see people in good faith believing in the content of the conspiracy theory. It's usually a tool to mount some war against a thorn jabbed in the speaker's side that they cannot articulate in polite company, so a conspiracy group is the next best place to hob nob and chin wag about this malefic thorn in their side, poisoning their thoughts and feelings and yet difficult to discuss without putting everybody to sleep with yet another impossible to solve fear.

The changes in view I've seen is when the underlying need to quell a fear has been met, the story they discuss openly tends to change a bit.