There's a joke within the intelligence community that you need a CIA badge to get into the McLean Family Restaurant, or MFR. The traditional diner is around two kilometres from the George Bush Center for Intelligence in Langley, making it one of the closest restaurants to the agency's headquarters.

In fact there's no need to show your credentials to enter this North Virginia institution, opened in 1969, which is now located in the heart of a typical small retail development with a chemist's, a barber's,