IMO an excellent blog/commentary from Bruce Schneier blog
Government Secrets and the Need for Whistle-blowers
Yesterday, we learned that the NSA received all calling records from Verizon customers for a three-month period starting in April. That's everything except the voice content: who called who, where they were, how long the call lasted -- for millions of people, both Americans and foreigners. This "metadata" allows the government to track the movements of everyone during that period, and a build a detailed picture of who talks to whom. It's exactly the same data the Justice Department collected about AP journalists.
The Guardian delivered this revelation after receiving a copy of a secret memo about this -- presumably from a whistle-blower. We don't know if the other phone companies handed data to the NSA too. We don't know if this was a one-off demand or a continuously renewed demand; the order started a few days after the Boston bombers were captured by police.
We don't know a lot about how the government spies on us, but we know some things. We know the FBI has issued tens of thousands of ultra-secret National Security Letters to collect all sorts of data on people -- we believe on millions of people -- and has been abusing them to spy on cloud-computer users. We know it can collect a wide array of personal data from the Internet without a warrant. We also know that the FBI has been intercepting cell-phone data, all but voice content, for the past 20 years without a warrant, and can use the microphone on some powered-off cell phones as a room bug -- presumably only with a warrant.