I think it's a useful discussion to have since there are so many people who "don't have anything to hide" The argument works well for privacy advocates because

I think it's a useful discussion to have since there are so many people who "don't have anything to hide" The argument works well for privacy advocates because even without regard to revealing classified secrets, the NSA won't be able to demonstrate good efficacy or good value for the money, due to the fact that such a system can only ever "work" rarely. A close look at this ought to also reveal a large fraction of abuse, and waste, in addition to false positives.