We must keep things in focus (how the heck did Quakers get brought into this conversation... ?)
Under FISA, an agent of a foreign power is defined as:
(1) any person other than a United States person, who–
(A) acts in the United States as an officer or employee of a foreign power, or as
a member of a foreign power as defined in subsection (a)(4) of this section;2
(B) acts for or on behalf of a foreign power which engages in clandestine
intelligence activities in the United States contrary to the interests of the United
States, when the circumstances of such person’s presence in the United States indicate that such person may engage in such activities in the United States, or when such person knowingly aids or abets any person in the conduct of such activities or knowingly conspires with any person to engage in such activities;
© engages in international terrorism or activities in preparation therefore
(2) any person who–
(A) knowingly engages in clandestine intelligence gathering activities for or on
behalf of a foreign power, which activities involve or may involve a violation of the
criminal statutes of the United States;
(B) pursuant to the direction of an intelligence service or network of a foreign
power, knowingly engages in any other clandestine intelligence activities for or on
behalf of such foreign power, which activities involve or are about to involve a
violation of the criminal statutes of the United States;
© knowingly engages in sabotage or international terrorism, or activities that
are in preparation therefor, for or on behalf of a foreign power;
(D) knowingly enters the United States under a false or fraudulent identity for
or on behalf of a foreign power or, while in the United States, knowingly assumes a
false or fraudulent identity for or on behalf of a foreign power; or
(E) knowingly aids or abets any person in the conduct of activities described in
subparagraph (A), (B), or © or knowingly conspires with any person to engage in
activities described in subparagraph (A), (B), or ©.
Also, a "person of the United States" is defined as:
The term “United States person” in FISA is used to describe a citizen of the United States, a permanent resident alien, an unincorporated association a substantial number of the members of which are U.S. citizens or permanent resident aliens, or a corporation which is incorporated in the United States.source
Congress amended the definition of "foreign power" in 2004 to include most terrorist organizations and even individual terrorists if they seek to do harm to the United States.
Now, FISA, first enacted in 1978, covers surveillance of foreign power (expanded to include terrorism). Domestic agencies (such as the FBI and DoJ) are expressly forbidden from using FISA to monitor persons in the United States because the intent is to monitor for intelligence gathering purposes and not for law enforcement purposes. (Note, there is still a "wall" between foreign intelligence gathering and domestic security agencies. Such a wall has been cited by former FBI director as a prime reason why the FBI could not track down the terrorist prior to their execution of the 9/11 attacks.)
FISA includes very specific instructions that the Attorney General must "minimize" any references to US persons.
FISA defines “minimization procedures” with respect to electronic surveillance in 50
U.S.C. § 1801(h). The term is defined under FISA with respect to physical searches in 50
U.S.C. § 1821(4). As the two definitions are similar, the definition from Section 1801(h)
is included for illustrative purposes.
(h) “Minimization procedures”, with respect to electronic surveillance, means–
(1) specific procedures, which shall be adopted by the Attorney General,
that are reasonably designed in light of the purpose and technique of the
particular surveillance, to minimize the acquisition and retention, and
prohibit the dissemination, of nonpublicly available information concerning
unconsenting United States persons consistent with the need of the United
States to obtain, produce, and disseminate foreign intelligence information;
(2) procedures that require that nonpublicly available information, which
is not foreign intelligence information, as defined in subsection (e)(1) of
this section, shall not be disseminated in a manner that identifies any
United States person, without such person’s consent, unless such person’s
identity is necessary to understand foreign intelligence information or
assess its importance;
(3) notwithstanding paragraphs (1) and (2), procedures that allow for the
retention and dissemination of information that is evidence of a crime
which has been, is being, or is about to be committed and that is to be
retained or disseminated for law enforcement purposes; and
(4) notwithstanding paragraphs (1), (2), and (3), with respect to any
electronic surveillance approved pursuant to section (1802(a) of this title,
procedures that require that no contents of any communication to which a
United States person is a party shall be disclosed, disseminated, or used for
any purpose or retained for longer than 72 hours unless a court order under
section 1805 of this title is obtained or unless the Attorney General
determines that the information indicates a threat of death or serious bodily
harm to any person. source
That's the groundwork, here's the meat:
Under FISA, the government (the Attorney General, actually) may authorize warrantless searches for a period of up to one year. The rules for doing such are covered under Section 1802 of Code 50: Electronic surveillance authorization without court order
(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; (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; and © the proposed minimization procedures with respect to such surveillance meet the definition of minimization procedures under section 1801 (h) of this title; and if the Attorney General reports such minimization procedures and any changes thereto to the House Permanent Select Committee on Intelligence and the Senate Select Committee on Intelligence at least thirty days prior to their effective date, unless the Attorney General determines immediate action is required and notifies the committees immediately of such minimization procedures and the reason for their becoming effective immediately.
The question is whether or not US person (i.e. US citizens, legal resident aliens, or US corporations) have been monitored. If they have not, then this is completely legal and even redundant to powers which have been available since 1978.
What has changed is the definition of "foreign power" which now refers to terrorists.
It is pretty unfortunate that such worthies as the Washington Post and New York Times have not tried to understand how this could be legal.
We don't know for sure that these activities pertain exclusively to non-US persons. The people covered are not known (to respect their privacy and to respect the secrecy needed in such investigations). However, considering the fact that the President and his legal advisors have decided that is is within bounds we can be relatively assured that they have at least reviewed this and are aware of the limitations. Had the President said that they were reviewing the legality, then I'd have some concerns.
Thus far, I have not seen a case where a US person has been the subject of these investigations. When I do, my position might change. Until then, I want the President doing everything in his power to protect us from terrorists.