A for whats it's worth guys....
In the early 1980's I was a Special Agent with the US Naval Investigative Service, a part of US Naval Intelligence at that time. Our charter was criminal investigation, and counter-intelligence and counter espionage investigations. While assigned to the Marine Coprps Logistics Base in Albany, Georgia, I submitted a counter-intelligence proposal to conduct covert surveillence and investigations of foreign flight students attending local area training schools. The purpose of the effort was to have been to identify, track, and maintain contact with these students to determine if any were involved in illegal or other acts detrimental to the national security interests of the United States.
The proposal was rejected because it would have violated the Church amendment prohibitions regarding domestic surveillence and gathering of intelligence of US citizens and aliens.
In light of current events, I guess I was just a bit ahead of my time there. How much you want to bet the Congress changes that law as a result of this tragedy.