Going back further, if you ever watched the movie Se7en, there's a scene where a one of the main characters in hushed tones mentions to another that the Feds set flags on certain library books so that people who check them out become "persons of interest" in the event that certain crimes are committed.

The first time I saw that movie was maybe 10 years after it came out (post 9/11; the move came out in 95 I think), and my reaction to that scene was "well duh".