I was offered a nice contracting job at a USAF base. All I had to do was run a single large Oracle server (Sun Enterprise 10000). I asked "what does the system do?" The recruiter told me the database handled the parts ordering system for foreign countries that need to order replacement parts for F-15 fighters that the US ships to them.

I turned down the position for ethical reasons. Somehow, I'm not comfortable knowing that I helped facilitate the export of US weapons systems to foreign countries that history has shown us are likely to use them to bomb their own people, or innocent people in their neighboring countries. The fact that most of these F-15s end up in middle eastern countries seems to be standard operating procedure for the US government. Then, later, when the next dictator they propped up starts bombing innocent civilians, the politicians will act outraged "who knew that by supplying weapons systems to a dictator he would ever turn them on innocent people?"

Sorry, but I don't want the blood of innocents on my hands. Working at the NSA might not directly be as damaging, but you better believe that people will die indirectly because of something you helped work on. Do you want that guilt on your conscience?