XKeyscore presentation from 2008 – read in full | World news | theguardian.com

Training materials for the XKeyscore program detail how analysts can use it and other systems to mine enormous agency databases and develop intelligence from the web

Revealed: NSA program that collects 'nearly everything a user does on the internet'

http://www.theguardian.com/world/interactive/2013/jul/31/nsa-xkeyscore-program-full-presentation