people that do installations for air force bases, navy, and of course area 51 because they have seen it all and they all have access to stuff like that. I am pretty sure area 51 has made threats if they were to ever tell anybody. So i dont know might be pretty hard to get it out of somebody oh and. Most of area 51 retired employees probly have a bunch of the area 51 watching there every move. Juts think about it would you want someone with million's maybe even billion's of dollar's worth of imformation just to walk away lol i dont think so. right?

they sign secrecy agreements as well....

Not to mention, for the super secret locations, they have their own branch of the Engineer Corps... Unlike civilians, they can be court-martialed, even executed, and away from public view....

Well said Gazrok

People who work in the armed forces all have to sign the Secrecy Act and some other documents...it's to protect themselves and others in times of crisis!

And....as for the Super Secret Locations.....emmm....well, don't wanna work in there?