Is the Surveillance Legal?
Volkh presents a clear discussion of the legalities of the Administration's wiretapping activities. In brief, he argues that the 4th amendment does not apply to the program in question due to the well-established border exemption that permits customs to search for contraband. The 1978 law FISA however is more complex: it prohibits electronic suveillance unless a few specific exceptions apply, or the executive is explicitly authorized by statute. Those exceptions are:
50 U.S.C. 1802(a)(1)
Notwithstanding any other law, the President, through the Attorney General, may authorize electronic surveillance without a court order under this subchapter to acquire foreign intelligence information for periods of up to one year if the Attorney General certifies in writing under oath that--
(A) the electronic surveillance is solely directed at--
(i) the acquisition of the contents of communications transmitted by means of communications used exclusively between or among foreign powers, as defined in section 1801(a)(1), (2), or (3) of this title; or
(ii) the acquisition of technical intelligence, other than the spoken communications of individuals, from property or premises under the open and exclusive control of a foreign power, as defined in section 1801(a)(1), (2), or (3) of this title; [and]
(B) there is no substantial likelihood that the surveillance will acquire the contents of any communication to which a United States person is a party.
Does this exception permit the monitoring? Note that (i) and (ii) are both dealing with "foreign power, as defined in (a)(1), (2), or (3) of this title." FISA's definition of "foreign power" appears in 50 U.S.C. 1801:
(1) a foreign government or any component thereof, whether or not recognized by the United States;
(2) a faction of a foreign nation or nations, not substantially composed of United States persons;
(3) an entity that is openly acknowledged by a foreign government or governments to be directed and controlled by such foreign government or governments;
(4) a group engaged in international terrorism or activities in preparation therefor;
(5) a foreign-based political organization, not substantially composed of United States persons; or
(6) an entity that is directed and controlled by a foreign government or governments
That's the key: the first passage cited definitions 1, 2, and 3, but did not cite 4,5, or 6. In other words, "a group engaged in international terrorism" is NOT a foreign power which qualifies an exception to FISA's constraints. Thus, I believe, with Volkh, that FISA prohibits the administration's activities.
The question then turns to the other possible avenue circumvent of FISA--whether there is a statutory mandate allowing such surveillance. The administration claims that the Authorization for the Use of Military Force supplies that statute, but the text really does not address surveillance, only direct military action, and Volkh points out that if Congress' intent was to create a surveillance mandate with the AUMF, why did they spend so much time amending FISA and passing the Patriot Act?
At the end of the day, the question must not be "Did this surveillance protect us from terrorists?" (how can we know?) or even "Did they break the law?" (forgivable if their interpretation is within reason) but "Did the administration act in good faith?" If it knowingly circumvented congressional oversight to spy illegally on American citizens, then it should face serious consequences.