A new leak published by The Guardian reveals more details about the NSA's Marina metadata program, including the program's ability to look back at a full year of metadata for millions of web users, regardless of whether the users are the target of an investigation. The metadata can include anything from browsing history to more detailed account activity in the case of web-based email, including contact lists and potentially even account passwords.

The Marina program had been mentioned in previous leaks, but the new revelations, pulled from an NSA training document, show how the data was centrally stored and managed. Much of the data is coming from previously reported programs, like PRISM's bulk FISA orders or GHCQ's undersea cable-tapping operations. Once collected, the data is put to build detailed graphs of a person's known associates and social activity, a process referred to in the document as "pattern-of-life development."