This page from GCHQ’s internal GCWiki, dated 27 May 2009 describes a system for querying mobile phone information acquired during port stops: see the Intercept article Airport Police Demanded An Activist’s Passwords. He Refused. Now He Faces Prison In The UK, 23 September 2017.
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.