We caught this in Snowden's Q&A from Thursday the 23rd:
"The second, less understood but far more sinister effect of these classified programs, is that they effectively create 'permanent records' of our daily activities, even in the absence of any wrongdoing on our part. This enables a capability called “retroactive investigation,” where once you come to the government’s attention, they’ve got a very complete record of your daily activity going back, under current law, often as far as five years. You might not remember where you went to dinner on June 12th 2009, but the government does." -- Edward Snowden
So do we.