From: https://en.wikipedia.org/wiki/John_Titor

John Titor is a name used on several bulletin boards during 2000 and 2001 by a poster claiming to be an American military time traveler from 2036.[1][2] Titor made numerous vague and specific predictions regarding calamitous events in 2004 and beyond, including a nuclear war, none of which came true. Subsequent closer examination of Titor's assertions provoked widespread skepticism. Inconsistencies in his explanations, the uniform inaccuracy of his predictions, and a private investigator's findings all led to the general impression that the entire episode was an elaborate hoax. A 2009 investigation concluded that Titor was likely the creation of Larry Haber, a Florida entertainment lawyer, along with his brother Morey, a computer scientist.