In the early - mid 1980's a BAe team at a famous USAF base were suddenly told to turn their backs, and not look on pain of being shot, when a mystery aircraft came in.
Full of it, aren't they??!! I was in Saudi during the build up to GW2. It wasn't hard to figure that something was up given all the American accents quacking away merrily on 243.0!
Couldn't keep a secret to save themselves!