People are wrong about the NSA. I promise you, they do not listen to your calls en masse. My proof? Let me pull up this quote:
There you go. What was that from? Donald Cooper of the ASA. Haven't heard of it? Probably because it's from East Germany in 1958.“We didn’t care what they were saying,” he says. “What we cared about was who was saying it, and where they were saying it from. Nobody was interested in listening to people’s conversations.”
Even some 50+ years ago, intelligence folks did not need to listen to calls, it's just expensive (manpower & techwise) and does not provide any more information than just listening to the meta-data.
Would you like a more recent example? How about the AOL Data Leak? AOL released anonymized information about search queries to researchers and it leaked out. Now, it had no information about the users, but researchers QUICKLY discovered people and what they were interested in - real people, not their pseudonyms or accounts.
Why would you waste time and money when all the information is there already? The fact is the NSA isn't not listening BECAUSE THEY DON'T HAVE TO.