Files reveal WW2 secret 'Agent Fifi' test for spies
bbc.co.uk
bbc.co.uk
http://en.wikipedia.org/wiki/Compartmentalization_%28informa...
Of course you could say there was a 'need to know' but at a minimum there should have been many 'Fifi's', and preferably ones that did not come from occupied territory.
They don't seem to have mentioned that this time around, so maybe that turned out to be just a rumour.
This is aside from the rather blindingly obvious solution of keep her busy... if the only guys she talks to are your spies, then when is she meeting these theoretical German spies?
Another problem is you vet 3000 people and its going to be extremely hard to describe them all. "Well, they look english, like bangers n mash, they say "bloody" and "god save the king" a lot, kinda average height..."
By contrast, another was let go because she carried on relationships with the trainees after they were sacked!