So, the slogan for the anti-cult group is a reference to a book about magical evil ghosts.

"Fight crazy with crazy" indeed.

This likely stems from the latter.

They suppressed the rest of us for 5000 years. Now it's our turn.

In some writings (I don't know what to call them, autobiographical notes, perhaps?) by Robert Heinlein and Issac Asimov, both who knew Hubbard personally as a sci/fi contemporary, they mention him musing the idea of starting a religion to make a shit ton of money off the suckers back in the late 40's. He launched it a few years later, and look at it now.

Too bad they didn't have some spaceship in a comet they could all kill themselves to get to (in their Nikes, or whatever self-respecting cultists wear these days).