Details ARE important.
Like:
"'United States person'' means a citizen of the United States, an alien . . . BUT DOES NOT INCLUDE a corporation or an association, which is a foreign power, as defined in subsection (a)(1), (2), or (3) of this section."
Yes, and that is the controversy, that it was United States persons, citizens, who were spied on without a warant...which is ILLEGAL.