So it has come to my attention that both the FBI and NSA have pages (FBI here and NSA here) for requesting copies of files (if any) that they keep on you. I would like to believe that for most people, no such file exists, but who the hell knows. I wouldn't be shocked to learn that something I've shared with the world online or in any other medium got me some unwanted attention, even if I'm not guilty of anything criminal per se.
Obviously if you were actually a serious threat in the eyes of the US domestic spying agents, there would be reason to doubt the transparency in whatever kind of response you received; I also am guessing that if there weren't a file on you before, asking for a copy of one would almost certainly lead to the creation of one. What I'm wondering is, has anyone ever done this, or known someone who has? And if so, what kind of response did the person get?