John Titor
In 2000 and 2001, a mysterious figure appeared on the Time Travel Institute and Art Bell's Post-to-Post forums claiming to be a military time traveler from 2036. He called himself John Titor, and he made many predictions about the future, including a nuclear war in 2004.
Titor's claims were met with skepticism, but he was able to provide some convincing evidence, such as knowledge of events that had not yet happened. However, his predictions were not always accurate, and in 2009, an investigation concluded that Titor was likely the creation of Larry Haber, a Florida entertainment lawyer, along with his brother Morey, a computer scientist.
Despite the fact that Titor was likely a hoax, his story remains fascinating and continues to capture the imagination of people around the world.