Blackmail is a worthwhile consideration. Considering how many politicians today are dethroned by some scandal or another, any scandalous data captured by the NSA would make for excellent leverage. Further, however, this simply highlights again the need for a restructured communications layer atop the internet capable of mixnet-style encryption. It's past time for there to be an affordable and simple way to onboard large numbers of people into Tor, I2P, Secushare, Bitmessage, and other such systems.