Article on NSA Surveillance Law:

Here is an interesting pre-Patriot Act student note on the law governing NSA surveillance: Lawrence D. Sloan, Note, ECHELON and the Legal Restraints on Signals Intelligence: A Need For Reevaluation, 50 Duke L.J. 1467 (2001). I gave it a quick skim, and it seems to present a decent background for some of the issues surrounding FISA and NSA surveillance. Thanks to reader Shawn Bjorklund for the link.