Like Henry Ford before him, Elon Musk has emerged as America’s top conspiracy spreader. But he’s hardly alone. Robert F. Kennedy Jr. is the conspiracy-theory candidate for president, and as Paul Krugman observed last summer, was attracting “support from some of the biggest names in Silicon Valley”:

Conspiracy theories are often regarded as unfounded beliefs that lack factual evidence. Nonetheless, it is worth noting that some of these theories have actually turned out to be true.

While science and technology has advanced by leaps and bounds, there still are people who shun their evidence and believe in conspiracy theories. Here we list 10 of the biggest and most famous conspiracy theories and what are the aftermaths of this belief.

Do you believe the moon landings were faked? Maybe you’re certain there was a shooter on the grassy knoll the day JFK was gunned down. Or perhaps you’ve got some alternative ideas about what happened on 9/11.