Such was the conundrum facing the maintainers over at the Museum of Hoaxes, who was one of many at the beginning of the century to receive spam emails asking for someone to sell the subject a "dimensional warp generator." The email went into great detail about specs for this device, which would include 512GB of RAM and a menu-driven GUI.
It turned out that the emails were being sent out by a known professional spammer who also happened to be delusionally insane. Wired breaks the straight story. Far from being a time traveller, Todino was a perfectly ordinary 22-year-old with a father in this present day who was worried about his son's mental illnesses being exploited by scammers online.
Make no mistake about it, this is actually a common problem with spammers. If you've ever received spam and wondered "who would ever fall for this?", the answer is, "nobody, actually, but authors of spam software and systems prey on gullible people who think they can make millions sending out spam. Big fleas got little fleas on their backs to bite 'em!
Todino (like the mythical John Titor, whom, remember, has never been positively identified) gained widespread Internet fame and cultural tribute, making this list of time travel claims, and being famous enough that there's dozens of accounts claiming to be him on Twitter, Facebook, LinkedIn, and so forth.
Sadly, no verifiable interviews with Todino exist on YouTube. So for second prize, here's a different kook who raves about time travel conspiracy theories: