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 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 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.