hard to find, most times a conspiracy theory fails, or is proven to be wrong, theorists behind 'em just move the goalposts, as it were. much like people who predict the end of the world... also, theorists tend to be fairly vague about future events or timescales, which makes it easier for them not to "fail" but very very good at recognising patterns retrospectively.
agreed. Every conspiracy guy I know just keeps moving the goalposts when I bring up a point that could prove their story wrong. I wish I could think of one that was open and shut but most people don't give conspiracy the time of day. p.s. ANCIENT ALIENS!!!!!!!!!!!!!!!! "I'm not saying it's aliens... but it's aliens"
not to mention that proof, no matter how compelling, is rarely accepted if it contradicts the narrative, flat earth conspiracy theorists, for example, refuse to accept any evidence that contradicts their biblical interpretation of geography. so you can't really say that the conspiracy theory "failed" because it is still alive and well, and although a fairly small amount of people believe in it, that can't be the criteria for whether or not a conspiracy theory "fails" because they are all believed only by a minority.
The KFC conspiracy certainly comes to mind, when I think failure. Really, the word idiotic describes it best. From what I remember, it has something to do with Colonel Sanders being an alleged member of the KKK and making the "famous herbs and spices"recipe for his chicken in such a way that it makes all black men go sterile. There's probably more to it but it's just to fucking stupid to remember all of it.
In the 50s and 60s, they was a fluoride conspiracy too but it was the godless communists who wanted to make us stupid so they could take us over. Now whenever you hear the words "communist plot" you think of some senile old person. Interracial marriage, also a communist plot. Marijuana was a communist plot. Conspiracies are more or less like a religion. You can't disprove them to the already convinced because they are structured in such a way that evidence can disprove them. Anybody who tells them otherwise is part of the conspiracy. They can make up shit and even if all the evidence is against them it's all part of the conspiracy!