But while the NSA's eavesdroppers have chipped away at some of the privacy safeguards that Internet users take for granted, there are still encryption technologies that they probably can't yet defeat.
Moreover, even less than state-of-the-art encryption still makes it sufficiently difficult and time-consuming for code-breakers to decipher messages that they can't conduct "dragnet" searches, in which they would sift through millions of users' emails, calls or chats in search of some word or phrase.
"Think of encryption as being like a safe," explained Ashkan Soltani, an encryption expert who consults with the Electronic Privacy Information Center, a Washington, D.C.-based watchdog group. "When you buy a safe, it's rated based upon the number of hours it would take an expert safe-cracker to break in. So you can buy a 5-hour safe, or a 30-hour safe, depending upon how much security you think you need."
Similarly, he explains, an encryption software developer can lengthen the key -- the sequence of numbers that unlocks the message -- or make the algorithms in the program more complex.