In ascending order of importance:
#5. Be sure to keep a copy of the U.S. Constitution on your desk and refer to it loudly around NSA employees whenever you see the NSA doing something you think violates the Constitution. (Also be sure to argue with NSA coworkers on the points in the Constitution.)
#4. Wear clothing with a logo that identifies you to NSA coworkers and your supervisor as someone who thinks the NSA is overstepping its mandate.
#3. Find and report as many holes in NSA security as you can, then set up a howl at NSA when they don't patch every security breach you've identified.
#2. Every time your top secret computer access turns up something you think the NSA shouldn't be doing, call coworkers in your department at NSA to gather around your computer and look. Harangue them to complain to their supervisors about what you've showed them. Harangue your supervisors at NSA as well.
And Ed's #1 tip to avoid suspicion:
Email NSA attorneys to tell them the NSA had better stop the illegal stuff it's doing and if it doesn't you'll take further action.
Yes, there is no better way to keep a low profile as a spy than by doing what Ed did at NSA. But then there is the Twilight Zone explanation as to why he couldn't get a hearing, no matter how much racket he made: everyone he complained to at NSA was actually a spy for China or Russia.
HaHa! Just joking! But then there was the time I joked on this blog that the Federal Reserve was alarmed about Americans who were stocking up on cans of creamed corn against the coming financial collapse. A couple months later I came across a report on the Internet that one of the activities Homeland Security considers a sign of a possible American terrorist is that the American stocks up on canned food.
Now if the report is true the question would be how Homeland would know who's stocking up. Would they review receipts at Costco and Wal-Mart? Or is this how NSA is spending part of its time; counting cans of Green Giant creamed corn and Dinty Moore beef stew? Or does the FBI have agents stationed in shopping mall parking lots across America on Saturdays who record the license plate of every person loading a case of canned food into the car?