Anticipatory Electronic Surveillance in Anglo-American Law (Stanford Technology Law Review)
The principles behind the Fourth Amendment’s Search and Seizure clause are found throughout Anglo-American jurisprudence. This body of law reflects a history of attempting to harmonize the seemingly conflicting governmental goals of communication privacy on the one hand, and protecting the public safety and national security on the other. Nations adopt surveillance doctrines, driven largely by the realities of the technology. As technologies change, assumptions behind doctrines can become outdated.
http://stlr.stanford.edu/2007/01/anticipatory_electronic_survei.html