NSA takes very seriously its mandate to do "what NSA does" against foreign entities and NOT U.S. citizens. The rules were clarified in the late 70's in the Foreign Intelligence Surveillance Act (FISA). FISA was written after the findings of the "Church Proceedings" were published as part of the fallout of the Watergate scandal.
I've only heard the Church Proceedings mentioned twice in my lifetime - once twenty years ago when I was investigated for violating the charter when I led a forensic team to help the Dept. of Justice after their website was defaced, and the second time was in hearing news reports about Edward Snowden. This is why I'm sometimes heard to say, "I was the first Edward Snowden".
I will share the story of how I was almost fired from NSA for violating the same law that NSA has been accused of violating based on the information disclosed by Edward Snowden several years ago. The goal is to shed some light on how NSA really operates, from someone who used to be on the inside, in order to take the whole Snowden debate to a different level. I do not intend to sway anyone's opinion, but merely want to offer some details that should help anyone make a more informed decision about NSA, its mission, and the laws by which it is governed.