This internal NSA post dated 13 April 2012 from the European Cryptologic Center in Darmstadt, Germany recounts an “XKS training blitz”: see the Der Spiegel article New NSA Revelations: Inside Snowden’s Germany File, 18 June 2014.

This undated GCHQ presentation proposes a deanonymisation attack against Tor users based on the collection of data from exit nodes owned by the agency: see the Der Spiegel story Prying Eyes: Inside the NSA’s War on Internet Security, 28 December 2014.

This internal NSA post from 14 March 2006 describes an incident on 20 December 2005 when what was suspected to be unexplodeded WWII-era ordnance was discovered at an agency facility in Mainz Kastel, Germany: see the Der Spiegel article New NSA Revelations: Inside Snowden’s Germany File, 18 June 2014.

This undated page from GCHQ’s internal GCWiki gives an indication of the agency’s thinking on the feasibility of Tor deanonymisation attacks: see the Der Spiegel story Prying Eyes: Inside the NSA’s War on Internet Security, 28 December 2014.

This NSA presentation from 1 October 2010 describes RAMPART-A, the agency’s “unconventional special access program”: see the Intercept article How Secret Partners Expand NSA’s Surveillance Dragnet, 19 June 2014.

This GCHQ presentation from 2010 describes the extent of the agency’s cable-tapping and plans for the future: see the Intercept article Profiled: From Radio to Porn, British Spies Track Web Users’ Online Identities, 25 September 2015.