From Glenn Greenwald's "On Security and Liberty" column:
Let's repeat that last part: "no digital communication is secure", by which he means not that any communication is susceptible to government interception as it happens (although that is true), but far beyond that: all digital communications - meaning telephone calls, emails, online chats and the like - are automatically recorded and stored and accessible to the government after the fact. To describe that is to define what a ubiquitous, limitless Surveillance State is.
That every single telephone call is recorded and stored would also explain this extraordinary revelation by the Washington Post in 2010:
Every day, collection systems at the National Security Agency intercept and store 1.7 billion e-mails, phone calls and other types of communications.It would also help explain the revelations of former NSA official William Binney, who resigned from the agency in protest over its systemic spying on the domestic communications of US citizens, that the US government has "assembled on the order of 20 trillion transactions about US citizens with other US citizens" (which counts only communications transactions and not financial and other transactions), and that "the data that's being assembled is about everybody. And from that data, then they can target anyone they want."