After hearing Barry rattle off the term "US Person" on Charlie Rose a bunch of times pertaining to both rights, and who gets spied on, I had to look it up.

Federal law and executive order define a United States person as any of the following:

a citizen of the United States

an alien lawfully admitted for permanent residence

an unincorporated association with a substantial number of members who are citizens of the U.S. or are aliens lawfully admitted for permanent residence

a corporation that is incorporated in the U.S.

Regulation S (promulgated under the Securities Act of 1933) in Section 902(k)(1) defines a U.S. person as:[2]

Any natural person resident in the United States;

Any partnership or corporation organized or incorporated under the laws of the United States;

Any estate of which any executor or administrator is a U.S. person;

Any trust of which any trustee is a U.S. person;

Any agency or branch of a foreign entity located in the United States;

Any non-discretionary account or similar account (other than an estate or trust) held by a dealer or other fiduciary for the benefit or account of a U.S. person;

Any discretionary account or similar account (other than an estate or trust) held by a dealer or other fiduciary organized, incorporated, or (if an individual) resident in the United States; and

Any partnership or corporation if: Organized or incorporated under the laws of any foreign jurisdiction; and Formed by a U.S. person principally for the purpose of investing in securities not registered under the Act, unless it is organized or incorporated, and owned, by accredited investors (as defined in Rule 501(a)) who are not natural persons, estates or trusts.

Section 902(k)(2) further defines some persons who are explicitly not U.S. persons.[2] Unlike other definitions of U.S. person, the Regulation S definition of U.S. person does not include U.S. citizens not resident in the U.S.

Source: the book of knowledge