My downvote was because you led off with an unnecessary personal insult to a new user in response to a polite and legitimate question. He created an account a week and a half ago, has made a few high quality comments (https://news.ycombinator.com/item?id=8614442), and I wouldn't want to see your rudeness drive him off, or worse, encourage him or others to respond in kind. The rest of your response was on-topic and well-argued, although like some of the others I think you might be unnecessarily equating the need for the NSA as a separate agency to the need for any form of foreign intelligence gathering.