I was more referring to the NSA leveraging power over our congressmen and senators due to their knowledge of secrets those politicians may not want exposed. That's a very dangerous game to play, and all it takes is one person not willing to play for it to all come tumbling down for the NSA. So, I don't really subscribe to that narrative.
I'm skeptical that the NSA would do that so explicitly (although given that Snowden's entire set of revelations consisted of "they wouldn't do that ..... oh they did" perhaps I should have less confidence).
I think a far more plausible and subtle form of mental pressure is simply manipulating secrecy and technical bullshit. You don't have to know a Congressman's porn preference to manipulate him if you can instead say, "we are tracking dangerous terrorists and if you don't do exactly what we want, they will win and it'd be an awful shame if an angry analyst leaked to the press the fact that YOU, CONGRESSMAN JONES, prevented us from doing our jobs".
Whether the terrorists really exist or not doesn't matter when you are effectively unauditable, and can easily imply that anyone who gets in your way is directly responsible for the deaths of innocents.
That's exactly it, but it's even simpler than that; when you control the reports that the political leaders are relying on for information, you control the set of options they can select from. Some things never get reported, others get reported such that there is an "obvious correct" choice. Coercive measures are possible, but they shouldn't be necessary in most cases.
Jacob Appelbaum describes this process very well in an interview[1] where talks about the time the CSE[2] tried to recruit him. It's hilarious... and scary for several reasons, including the suggestion that the CSE has to get NSA approval for the people they hire.
