An opinion from an Associate Professor of Law at GWU:

...Did Bush Have the Legal Authority to Authorize NSA Surveillance?
http://www.concurringopinions.com/archives/2005/12/so_whats_bushs.html

>From the post:
   In engaging in the surveillance, the President may have ignored the
legal procedures set forth in the Foreign Intelligence Surveillance Act
(FISA) of 1978.

   The FISA allows the government to engage in electronic surveillance
if it obtains a court order from the Foreign Intelligence Surveillance
Court (FISC), which meets in secret. The government must demonstrate
probable cause that the monitored party is a "foreign power" or an
"agent of a foreign power." 50 U.S.C. § 1801. If the monitored party is
a U.S. citizen, however, the goverment must establish probable cause
that the party's activities "may" or "are about to" involve a criminal
violation. Id.

   FISA even provides procedures for surveillance without court orders.
Such surveillance, however, must be "solely directed" at gathering
intelligence from "foreign powers" and there must be "no substantial
likelihood that the surveillance will acquire the contents of any
communication to which a United States person is a party." 50 U.S.C. §
1802(a). The surveillance authorized by the President, however, involved
U.S. citizens, thus making § 1802 unavailable.

   FISA also has § 1844, which provides that "the President, through the
Attorney general, may authorize the use of a pen register or trap and
trace device without a court order under this subchapter to acquire
foreign intelligence for a period not to exceed 15 days following a
declaration of war by Congress." 50 U.S.C. § 1844. I don't know many
details about the timing of the surveillance, but regardless of timing,
the surveillance appears to have far exceeded the limited authorization
in § 1844. The NY Times article suggests that the NSA may have engaged
in wiretaps or other forms of electronic eavesdropping extending far
beyond pen registers or trap and trace devices, which merely provide
information about the phone numbers dialed.

   Thus, it appears that the President brushed FISA aside. . . .


Daniel J. Solove

Associate Professor of Law

George Washington University Law School