I made the argument that I did because the public justification for the NSA is terrorism.<p>But I could have made a different argument focused only on the merits of spying.<p>Yes, it is obviously helpful to steal secrets.  Yes, this gives us an edge in negotiations, allows us to steal technologies, and so on.<p>However people get pissed off at us when they discover that we have done so.  See Angela Merkel&#x27;s cellphone.  Some of our attempts to assist spying leave us open to harm.  See backdoors deliberately left in software that black-hats later discover.  Lack of trust has a cost.  I&#x27;ve seen estimates that US companies have lost tens of billions of dollars in contracts because other countries don&#x27;t trust us with their data.<p>And when everyone knows that we spy, everyone else is likely to spy back just to level the playing field.  But spying is asymmetric; small players can do it effectively with very little in the way of resources, and  big players have more to lose.<p>When I put together everything I know, I believe that our aggressive spying programs are a net economic loss for us.  We could be better off by spying in a much more targeted way, but with very large penalties for anyone who we caught spying on us.<p>Obviously I have biases and incomplete information.  But I&#x27;m not convinced that spying is a good justification for the NSA, even if we were honest with ourselves about it.