Robert Philip Hansen is a former Federal Bureau of Investigation agent who spied for Soviet and Russian intelligence services against the United States for 22 years from 1979 to 2001. Wikipedia
FBI not NSA!
And you think the NSA is not susceptible to the same short comings. I think they are much more susceptible to corruption because they deal so intimately with it and at the highest levels. I know who Hanson was, I merely used him as an example of how easy it is to hide within.