My roommate had gone to Cuba in about 1965. He lived in my Apt for about 6 months after he came back and then went on with his life. FBI came by every year to ask about him ( for some reason they could keep track of me but not him
). The same guy came for about 5 years and he was always polite. Then a new guy started showing up, a real jerk. The second year he came I refused to show him my ID. He let it pass and left. Haven't heard from the FBI since.