As i responded in that thread... it sounds like the wiretapping becomes illegal if the U.S. citizen is not an agent of a foreign power.
Well sure, but does that mean that even if you are a citizen you cash in your abovementioned rights by collaborating with terrorists? Yes you do. You have then become an "Agent of a foreign power" as defined under subsection (b)(2)(C). Such agents include anyone who "knowingly engages in sabotage or international terrorism, or activities that are in preparation therefor, for or on behalf of a foreign power," and even includes those who aid and abet or knowingly conspire with those engaged in such behavior.