That is the Government line. But, I believe it is a false argument (i.e. propaganda). Schneier (popular on here) spells is out clearly,
https://www.schneier.com/blog/archives/2013/07/michael_hayde...I disagree (mildly) with his first point that operationally the US is affected. Because it's been a long held assumption that the US had extensive spying programs in place. Snowden simply provided the evidence. So, if you had something to hide from the NSA you were already hiding it as best as you could. Maybe, now a few more attack vectors have been revealed and hiding/encryption practices will be updated.