http://www.eff.org/Censorship/Terrorism_militias/fisa_faq.html<snip>
3. How does FISA fit with regulation of electronic surveillance?
Given the "tendency of those who execute the criminal laws . . . to obtain conviction by means of unlawful seizures," the Supreme Court has viewed commumications interception as an especially grave intrusion on rights of privacy and speech. Berger v. New York, 388 U.S. 41, 50 (1967) (quotation and citation omitted). "By its very nature eavesdropping involves an intrusion on privacy that is broad in scope," and its "indiscriminate use . . . in law enforcement raises grave constitutional questions." Id. at 56 (quotation and citation omitted). "Few threats to liberty exist which are greater than those posed by the use of eavesdropping devices." Id. at 63.
Thus, the Court outlined seven constitutional requirements: (1) a showing of probable cause that a particular offense has been or is about to be committed; (2) the applicant must describe with particularity the conversations to be intercepted; (3) the surveillance must be for a specific, limited period of time in order to minimize the invasion of privacy (the N.Y. law authorized two months of surveillance at a time); (4) there must be continuing probable cause showings for the surveillance to continue beyond the original termination date; (5) the surveillance must end once the conversation sought is seized; (6) notice must be given unless there is an adequate showing of exigency; and (7) a return on the warrant is required so that the court may oversee and limit the use of the intercepted conversations.
Indeed, the Court said that if "neither a warrant nor a statute authorizing eavesdropping can be drawn so as to meet the Fourth Amendment's requirements . . . then the Ôfruits' of eavesdropping devices are barred under the Amendment." Id., at 63.
Where intelligence operations are concerned, however, the bounds of the Fourth Amendment are less clear than they are for ordinary criminal investigations. FISA creates a special court and legal regime for counterintelligence surveillance orders.
Executive Order 12,333 (1981) provides the general framework for U.S. intelligence activities, and it also addresses electronic surveillance. "
gencies are not authorized to use such techniques as electronic surveillance, unconsented physical searches, mail surveillance, physical surveillance, or monitoring devices unless they are in accordance with procedures established by the head of the agency concerned and approved by the Attorney General." EO 12,333, para. 2.4. Dep't. of Defense (DOD) Directive 5240.1-R implements FISA and EO 12,333 within DOD. These authorities govern the collection of intelligence by the U.S. government against United States persons, whether they are located within the United States or outside the United States.
FISA does not regulate the use of electronic surveillance outside of the United States. For instance, electronic surveillance of electronic communications like e-mail is only governed by §1801(f)(4) if the surveillance device is installed "in the United States." When e-mail sent by a U.S. person to a foreign person is intercepted outside the United States, that interception does not meet this definition.
<snip>
More good stuff here