This draft report from 12 February 2010, prepared by officials from the UK intelligence services for review by the Cabinet Office and HM Treasury is frank about the challenges brought about by bulk collection: see the Intercept article Facing Data Deluge, Secret U.K. Spying Report Warned of Intelligence Failure, 7 June 2016.
This 14 September 2011 post from the NSA internal newsletter SIDToday from the agency’s Cryptanalysis and Exploitation Services division explains why ubiquitous encryption presents a “major threat” to the agency: see the Der Spiegel story Prying Eyes: Inside the NSA’s War on Internet Security, 28 December 2014.
This 40-page NSA presentation for the June 2012 SIGDEV conference includes a ranking of cryptographic protocols in order of ‘risk’ the they pose to the agency’s operations: see the Der Spiegel story Prying Eyes: Inside the NSA’s War on Internet Security, 28 December 2014.
This internal NSA briefing dated 17 January 2013 describes the current state of the US-German intelligence relationship and mentions that “The BND has been working to influence the German Government to relax interpretation of the privacy laws over the long term to provide greater opportunity for intelligence sharing”: see the Der Spiegel article New NSA Revelations: Inside Snowden’s Germany File, 18 June 2014.
This short extract from an NSA document shows that cooperation with Germany’s intelligence services went as far as providing the country’s domestic intelligence service, the Federal Office for the Protection of the Constitution (BfV), with access to XKeyScore: see the Der Spiegel article New NSA Revelations: Inside Snowden’s Germany File, 18 June 2014.
This internal NSA post from 10 June 2011 describes the further evolution of US-German signals intelligence cooperation and the focus of the NSA’s “long-term mission presence in Germany”: see the Der Spiegel article Terrorverdächtige: NSA nutzte Erkenntnisse aus Deutschland-Filiale für Tötungen, 15 June 2014.
This background document, prepared by NSA officials in advance of a conversation with representatives of Germany’s domestic (BfV) and foreign (BND) intelligence services, outlines the continuing cooperation between the three agencies in the field of counterterrorism. Extracts from this document were published by Der Spiegel in July 2013: see the Der Spiegel article New NSA Revelations: Inside Snowden’s Germany File, 18 June 2014.
This undated presentation from the NSA’s Special Source Operations division shows that the agency’s ability to intercept key communications infrastructure is dependent on corporate relationships, several of which can be identified using information given in this document: see the Guardian article Snowden document reveals key role of companies in NSA data collection, 1 November 2013.
A 2012 report from GCHQ describes a method of “staining” electronic traffic to distinguish between anonymous Tor users: see the Washington Post article Secret NSA documents show campaign against Tor encrypted network, 4 October 2013.