sophisticated investigative authorities. You do not get to search warrants, you don’t get to subpoenas, you don’t get to listen in on a subject’s communications through a FISA or Title III court order, without people telling you what they know. And if you can’t credibly tell them that you will protect and conceal their identity if they are willing to go out on a limb, if they are willing to risk their own and their families’ lives and welfare—if they can’t trust that you will protect them—then they will not cooperate with you.
