[malandrew]

True, yet I imagine it shouldn't be difficult to signal out those employees that present the greatest HUMINT risk and apply extra scrutiny. Any employee that have any sort of top secret clearance, that has worked for intelligence agencies or contractors and the worked in the military, but not out in the field is potentially a mole.

I'd find it hard to believe that there are people that don't fit that profile but are moles for governmental intelligence agencies even exist.

[toyg]

People come to Google from all paths of life. For all you know, some 20-something long-haired unix hotshot could have been busted for drugs at some point and "repurposed" as a mole in exchange for leniency. And there's always the classic sex honeytrap for married men, which will never go out of fashion.

Real spooks don't carry a conscience, they'll exploit anything they can to get their grubby hands on the data they need.

[malandrew]

    "For all you know, some 20-something long-haired unix 
    hotshot could have been busted for drugs at some point and  
    "repurposed" as a mole in exchange for leniency."

Excellent point. Previous comment retracted.