Like the movie said: “It’s Complicated!” No Such Agency operates within legal boundaries. Those boundaries are the product of a special court.
Please remember this: The folks working at the different NSA locations are Americans. They are not bio-replicates or robots. These workers are you and me and not something an alien pooped on the sidewalk to hatch.
For the most part they are Army, Navy, Air Force and Marines.
In many cases they serve the nation in far remote locations. They give up most of the “comforts” in life and also they are away from their families. They do this to protect our Constitution and Country.
They can never talk about their jobs. Many go on special tasking missions without any assurance that they will return.
And you will never know who they are!