IMHO, the leaders of the world have already negotiated with the aliens about a coexistence. They will not disclose their existence as long as they can sample a few humans once in awhile.

I'm a big fan of Coast to Coast. Thursday night (central time), John Lear, a UFO expert, will be on the show.

Richard C. Hoagland is is a frequent guest who makes convincing arguements about alien structures on the moon. His site looks a bit fake but you can check it out here.