Just assume everything you say and write is being recorded. Because it is. Literally every bit that traverses the Internet is being recorded by the NSA in their massive data repositories. We're talking so much data storage capacity that it is measured in zettabytes (10^21 bytes). To appreciate the scale of their data storage operations, it could store audio recordings of every word ever spoken by every human being who ever lived (42 zettabytes of storage with a 16 kHz audio recording).
Every email, every post to a forum, every telephone call, and excuse me if I have to put on the tinfoil but I dare say all the new Internet-connected appliances like "smart" TVs are probably snooping on even the words you speak in your own living room. Storing the data is less of a daunting task than mining it for useful information later, but just the fact that they're storing it all means their intention is to use it against the citizenry.