Here is NSA's own brief "career path" page for mathematicians:
And here a decade+ old account by someone of what it's like to be interviewed by the NSA for a mathematics position:
Also, Cathy O'Neil's ("MathBabe") "uber creepy" review of being briefly courted by the NSA at one point:
The timing of the Snowden leaks was a bit of synchronicity for me, as I am currently reading "The NY Times Book of Mathematics" (an anthology, that I highly recommend, to lay readers especially) and had just reached chapter 5, which focuses on cryptography, where almost every reading includes mention of the NSA... interestingly, there was a time when a lot of friction existed between NSA and academic mathematicians who were being forced to work under various constraints by the governmental agency).
Anyway, for more info on the agency, there is of course a Wikipedia page for NSA here:
(BTW, if PRISM interests you, you may want to be sure you're familiar with ECHELON and Carnivore as well.)
Regular readers here know that I'm a huge fan of Keith Devlin, and for more than his mathematical writings. Coincidentally, he briefly worked for the NSA at one time, and on Twitter, has expressed major concerns since the NSA disclosures -- indeed, of over 200 math/science persons I follow on Twitter I've not seen anyone more vocal than Keith in his upset with the Government (and support for Snowden) in this matter.
He wrote a recent piece for HuffPost below on the subject, though it just scratches the surface:
He exhorts a kind of statistical (or "sense of risk") argument before ending thusly:
"Are we really, as a nation, going to give up personal freedoms that are the envy of the world -- a beacon to humanity -- because of a collective numerical stupidity which could be eradicated in a single generation by a small change in K-12 education?"The unnerving part is, that I suspect at least 50% of the citizenry will answer "yes" to that....
Fear is a powerful stimulus (and political tool)… and we, or at least our leaders, have been living in fear since 9/11/2001.
(Little wonder that sales of George Orwell's 60+ year-old novel "1984" have skyrocketed since the Snowden story broke.)