Chris123NT, on 11 December 2012 - 13:29, said:
You mean Stargate could be real?
lol

Strangely Stargate made a point of this in the episode with Wormhole Extreme. Should someone leak information about the Stargate Project they would just point to the Wormhole Extreme TV series and say its made up.
Same conspiracy theory applies here, make films about Aliens and secret agencies and then when information about them really does leak people will just say its from a film etc.
Plausible Deniability
Until I see it with my own eyes though I will always be a sceptic, even if it does exist does it really affect me as a person in my daily life?
Edit - Also prior to Barack Obama being in power there was a rash of films/tv series with black presidents in them, google it there is a discussion somewhere iirc in depth. Same theory goes, if you watch trends in films/tv things get presented to make the public more accepting when it actually occurs. Interestingly there is more proof behind a tehory like this than there is aliens. But also if you subscribe to this theory we could possibly be finding out about aliens in the very near future