The ACLU has a good discussion of how the NSA's massive grab of so much data is going to come back and bite the NSA
, not just because its efforts are likely to be at least somewhat restricted by Congress, but because the overreach is so egregious and so extreme, that the "happy accident" that makes much of it work -- the fact that so much internet traffic routes through the US -- may go away as a result. Basically, all of the concerns raised about the level of surveillance means that many other countries are now much more interested in making sure that their internet traffic doesn't need to go through the US.
If the U.S. government had confined its spying to the kind of targeted espionage and anti-terrorism activities that the public probably imagined the NSA was focused on, I think it would have been on safe ground internationally. The world knew about the NSA and its global eavesdropping activities, and is not shocked by espionage as traditionally practiced by many nations.
[....] The NSA today justifies its activities principally as a means of keeping the nation safe from terrorism. Ironically, had the United States eschewed dragnet spying and stuck with targeted foreign intelligence-gathering, it would not now be threatened by “data flight” and might remain in a better position to investigate genuine threats through the kinds of targeted eavesdropping efforts that the world does find acceptable.
This is almost certainly true. If the NSA had
remained focused on things like stopping terrorism, people wouldn't be so concerned. But the massive "collect it all" scope that it decided to embrace has made the whole thing a debacle for the NSA, which easily could have been avoided if it had continued to stick to its actual mandate.