It was one of the final questions of the NSA's open Q&A today, and one that's weighed heavily on the minds of American citizens since the Prism scandal last year: "Are our fears of being discreetly spied on merited?" They aren't, according to NSA Civil Liberties and Privacy Director Rebecca Richards . "NSA is a foreign intelligence agency," she explained. "Our mission is to collect critical intelligence on foreign powers or their agents necessary to defend the country." The response is almost dismissive, but technically correct: the NSA isn't supposed to keep tabs on domestic threats, that's the FBI's job. That said, Richards did admit that some intelligence collection against US citizens is unavoidable. "For example, a foreign intelligence target may communicate with or about a U.S. Person," she explained. "NSA's minimization procedures have been designed to account for this possibility and other cases where NSA may incidentally acquire U.S. Person information."