This page from GCHQ’s internal GCWiki, last edited in May 2012, provides background information on the agency’s “internet buffer business capability”: see the Der Spiegel article The NSA in Germany: Snowden’s Documents Available for Download, 18 June 2014.
Edward Snowden will be answering questions submitted by the public on his official support site, freesnowden.is, this Thursday 23 January at 8pm GMT, 3pm EST. The support site is run by The Courage Foundation and is the only endorsed Snowden Defence Fund.
This is the first Snowden live chat since June 2013 and will last for an hour starting at 8pm GMT, 3pm EST. Questions can be submitted on twitter on the day of the event using the #AskSnowden hashtag. Edward Snowden’s responses will appear at http://www.freesnowden.is/asksnowden
This 32-page NSA presentation dated 25 February 2008 details XKeyscore, a tool used to search unfiltered internet traffic in real time. Two slightly different versions of this presentation have been published; both follow below: see the Guardian article XKeyscore: NSA tool collects ‘nearly everything a user does on the internet’, 31 July 2013.
Nineteen slides from a 41-slide April 2013 NSA presentation describing the PRISM collection of data via internet service providers, “the SIGAD most used in NSA reporting.” Slides have been published gradually by several media organisations: see the Washington Post article NSA slides explain the PRISM data-collection program, 6 June 2013.