Conspiracy Theories

Oliver Stone's "JFK" (1991) stars Kevin Costner, Joe Pesci, Tommy Lee Jones, and a host of others. The film makes a case for a conspiracy of anti-Castro zealots, FBI, CIA, and other organizations rather than Lee Harvey Oswald acting alone to kill President Kennedy.

Paul McCartney was rumored to have died in an auto accident in 1966, but the news was suppressed to avoid mass hysteria among their fans. 

Supposedly, a professional McCartney impersonator, named either Barry Pepper or Billy Shears, was brought in to take Paul's place and clues were left in Beatles' songs and photographs. 

1997's "Conspiracy Theory" features Mel Gibson as a cab driver who was unwittingly part of the CIA’s secret MK Ultra project and suffers continuing paranoia. The film makes use of numerous conspiracy theories while Gibson's and Julia Roberts's characters try to find the truth of what actually happened. 

The birther movement is a vast conspiracy that alleges that Barack Obama was not actually born in the United States and was therefore ineligible to serve as president. The gist of this theory, posited by many prominent conservatives, is that Obama's birth certificate is a forgery.

The crash and recovery of a weather balloon outside Roswell, New Mexico, in 1947 did not gain traction as an alien conspiracy theory until the late 1970s. Since then, Roswell has capitalized on the event, going so far as to include a "little green man" on the city's official seal.