When I was at NSA in the early 80s, I heard rumors that a lot of UFO reports were our own experimental aircraft and early drones; but I didn't work in any department that would be directly involved in something like that, so can neither confirm nor deny. My strong impression from having worked there though is that the NSA would much rather civilians think aliens are visiting earth than compromise our intellgence gathering capabilities.
I'm not anti-Christian. I'm anti-stupid.