This 2005 post from the NSA’s internal newsletter SIDToday explains how the agency overcame the obfuscation of IMSI codes by mobile phone companies: see the Intercept article NSA Used Porn to “Break Down Detainees” in Iraq — and Other Revelations From 297 Snowden Documents, 1 March 2018.
This 49-page March 2009 NSA presentation explains how to conduct searches within XKeyScore: see the Intercept article XKEYSCORE: NSA’s Google for the World’s Private Communications, 1 July 2015.
This April 2010 GCHQ report proposes an automated approach to seizing large numbers of mobile phone encryption keys: see the Intercept article The Great SIM Heist: How Spies Stole the Keys to the Encryption Castle, 19 February 2015.
These six slides from 2010 GCHQ presentation outline the results of a trial operation to acquire SIM encryption keys: see the Intercept article The Great SIM Heist: How Spies Stole the Keys to the Encryption Castle, 19 February 2015.
This undated joint GCHQ/CSEC presentation provides an overview of “exploring and exploiting leaky mobile apps”: see the Der Spiegel article The Digital Arms Race: NSA Preps America for Future Battle, 17 January 2015.
This NSA Point Paper dated 22 February 2006 provides a history of the CRISSCROSS and PROTON information sharing systems that preceded ICREACH: see the Intercept article The Surveillance Engine: How the NSA Built Its Own Secret Google, 25 August 2014.
This ODNI briefing from 15 May 2007 describes the rationale for ICREACH and the scale of metadata sharing that was envisioned: see the Intercept article The Surveillance Engine: How the NSA Built Its Own Secret Google, 25 August 2014.
Two images from an NSA presentation describe Dutch-US cooperation in an international mission against Somali pirates in which signals intelligence was used to map contacts and support a naval mission. Identifying and technical details have been redacted: see the NRC Handelsblad article The secret role of the Dutch in the American war on terror, 5 March 2014.
This NSA presentation from May 2010 describes the kinds of information the agency can extract from smartphone traffic, describing the use of mobile apps as a “golden nugget”. Note that this is the first version of this document released online: see the Pro Publica article Spy Agencies Probe Angry Birds and Other Apps for Personal Data, 27 January 2014.