Lots of people have commented, of course, so there's not a lot that I can add, but let me say the following. One, surely the most trustworthy source - certainly more trustworthy than, say, Obama - on this is Ed Snowden himself, right? If he says that any analyst with sufficient clearance can target anyone at anytime, surely you should believe that, at least for the time being? Which leads us to the view that, just perhaps, the NSA is putting pressure on Obama, rather than the other way around, as suggested by commenter roystgnr here. If that's a little too spy novel for you, I'll say J. Edgar Hoover. Anyway, let me link to some pages, which I found useful: Bruce Schneier, brings the security expert's perspective to the table, and Arnold Kling provides a short political theory treatment. Steve Sailer wonders whether he's being paranoid. The Guardian has a page for people who have trouble telling PRISM from Verizon, compiled by Ian Black. May you all be safe in your homes.