It seems common on some other sites to state that the Fnord theory is not falsifiable - in fact searching for "fnord falsifiable" on google gives several very similiar results.

This is not true. To begin with, there is no perfect conditioning - and anyone who broke this sort of conditioning would very likely point the fnords out to his/her friends - the idea would spread too quickly to be surpressed.

Also, typesetting is largely automated now - it may not have been when Illuminatus! was written, I am not sure. If more characters were in an article than were visible, or if one required more space on the page than the author wrote it, editors would undoubtedly notice something was amiss. In short, the Fnord conspiracy theory is nonfalsifiable in only the sense that all conspiracy theories are. Some cranks will always feel that anyone denying the conspiracy MUST be part of the conspiracy, and to them no conspiracy can be falsified.