In my mind, the core reason not to work for NSA is that their organizational values and behavior are incompatible with our Constitution and with civil society.

In my mind, the core reason not to work for NSA is that their organizational values and behavior are incompatible with our Constitution and with civil society. Some people think that's important, some people don't, some people don't view the NSA's values and behavior the same way that I do. I think the most important thing is for your friends to think about whether or not the NSA is compatible with their ideas about the rule of law and about decent human behavior. If they can look clearly at what the NSA has done (directly, and what they've supported such as secret torture, secret prisons, indefinite secret detention without due process, drone strikes against children, etc) and say they want to help do that some more, I'm not sure anything can be done for your friends. If they were my friends, I'd tell them "goodbye", just as I would if someone I was close to wanted to join the KKK or become rapists. Once they're inside the national security system, they're unlikely to voluntarily associate with people who don't share those values, both because of the personal discomfort and because of the risk to their security clearance.