At this point it is reasonable to say it is probably a hoax. There is some evidence which suggests that, and which points to certain people I'm not going to name, except there happens to be an "innocent" explanation for their actions as well (which is why I won't name them).
If it is a hoax, some evidence may surface in between twenty and forty years. The people involved, if involved, are still fairly young. If it is not a hoax, that does not mean that things will happen as John Titor said they will.
I frankly regard his story as a cultural expression of an American Nativism whose basis in reality is passing. I believe it reflects what has been going on about as well as those who blame Obama for all our current ills, and miss both how he continues some (horrible) policies of the Old Administration and how he is making good substantive changes to the structure of his Office -- which will probably be reversed the next time republicans get in even though the country can literally NOT afford it (he's been hailed in the technical press as the most technologically savvy president since Hoover, who was an engineer by profession. He is literally bringing down the cost of IT in government to a Far greater extent than Clinton, whose limited efforts to do that were systematically reversed by the Bush Administration at the cost not just of money but at one point at the cost of the Country's ability to comply with a court subpoena. We had had the capablility to store those records until Bush people switched to Windows from Unix).
If he's from the future I don't believe he's given us an unbiased account of what happe4ned, nor do I (for reasons both occult and about Physics), that there is an immutable future and he may well have come back and insured he won't happen.