First line of defence. We do audits.
Turns out that isn't going to work out. Snowden's own example demonstrates it. The NSA surveillance system is swiss cheese for internal operators.
So this is going to be the NSA's end-game defence.
They're shocked. Shocked! Rogue actors were navigating around NSA's filters to access the NSA's information treasure trove. And now they know it, they will pursue a few of those folks diligently under the law and will resolve to train everyone else.
Whereas Snowden said the NSA's filters were deliberately weak so operators could disregard them. The NSA was happy for the operators to abuse the privacy of users so long as the NSA got the results they wanted.
Snowden has shown how the NSA's policy can backfire spectacularly.
The folks who designed the weak system and enabled the abuse of privacy are the real criminals. But they won't be punished.