[Apocryphon]

Conspiracy theories tend to encourage syncretism. It's as easy to disbelieve the official narrative on one subject and to substitute it for a theory, as it is to do the same to another. Different theories are but different crimes from the same culprits.

[mcguire]

And fun, when you start finding links between different theories.

Eco wrote novels about it.

[Apocryphon]

As did Robert Shea and Robert Anton Wilson.