Conspiracies come in many shapes and forms, so I need to be reasonably clear in declaring that I'm not talking about "real" sort that included secret plans to overthrow governments or nations, or boardroom plots to seize power and take over businesses.
I'm in the area where stories, myths, legends and "facts" build up around actual events with some sort of significance, and enough uncertainty around their facts for speculation to flourish, and gain some sort of pseudo-credibility, not because it can be proven, but more because it can't be disproven.
Classically UFOs, or rather flying suacers and alien visitations, claims that the moon landing was a hoax, or that there's a monster in Loch Ness (but please forget that one, for tourism's sake).
I recently had reason to write a short account of Rudolf Hess' flight from Germany to Scotland on May10, 1941. Foolishly, I thought this could be achieved in a few lines – mistake! The final page was huge, and even that was only 25% of the material I collected, after retaining only those details which were citable as facts relating to the event.
Having to review so much of the material in a short space of time was educational though. Reading through so many of the conspiracy theories back-to-back, together with the straightforward accounts, made it clear that the theories were largely fabricated around the carefull 'filling-in' of gaps in the account, and astute trawling of records of the time to locate similar items that could be referred to, and claimed to have a relation to the core event. Through the passage of time, repetition, and discussion, these theories become established, and gain a degree of credibility from their longevity, if not factual content.
A second trait also appeared during this review, and there can be little doubt that there are authors who have little better to do than tap into the 'conspiracy market' by searching for such stories, tying them together and releasing a 'sensational' book claiming to uncover the conspiracy they have discovered.
While I don't decry them for writing a good book, I do have a problem with the presentation of the content as fact, or pseudo-fact, and the unfortunate way it can move into popular culture, eventually being referenced as an actual account of subject in later years. History is the real loser in these cases, while the authors laugh all the way to bank, never to be held truly accountable for the unwitting damage they have done.