It simply doesn't wash, all this conspiracy theory.

It's too convenient to say there is a big cover-up and that we're all being kept in the dark. I saw a couple of UFO's when I was a teenager. One was a sighting five of us all watched from the top floor of our school, which we reported to our science teacher, who had a brother who worked in the local air traffic control who confirmed the object had been picked up. But so what? It might be an alien spaceship, but it could have been any number of other things too.

No physical evidence - that's the truth of it; apply Occam's Razor, and the whole alien/government theory just doesn't stand up.