A hoax is not a hoax until proven otherwise....

http://www.sightings.com/general/enchilada.htm
http://www.zetatalk.com/theword/tworx195.htm
Jim Marrs' interview excerpts...

--What do you make of the theory that Kennedy was assassinated because he intended to release information on the UFO phenomenon?

I have come across a lot of evidence to support this. For example, there is a 1962 CIA document that records the contents of a wire-tapped conversation between Marilyn Monroe and Hollywood reporter Dorothy Kilgallen two days before Monroe died. During the call, Monroe tells Kilgallen that JFK had told her of his visit to a secret air base where he viewed things from outer space. Kilgallen believed this was connected with the Roswell crash.

Certainly, an FBI document of July 1947 confirms that Kennedy knew about Roswell. Additionally, Bill Holden, it steward on board Air Fore one, reported a conversation that he had with Kennedy in 1963, in which he asked the President what he thought about UFOs. Kennedy became very serious and replied `I would like to tell the public about the UFO situation, but my hands are tied.'

However, there is evidence that, on 12 November 1963, Kennedy ordered the CIA to hand over all UFO documents to the White House, and this was two weeks before he was shot.