This 2012 post from the NSA internal newsletter SSO News is one of a series collated here related to the extension of the agency’s FAIRVIEW collection to eight sites in major US cities: see the Intercept article The Wiretap Rooms: The NSA’s Hidden Spy Hubs In Eight U.S. Cities, 25 June 2018.
This post from the NSA’s internal SIDToday newsletter, dated 6 May 2010 and attributed to the Menwith Hill station describes NSA, CSEC and GCHQ’s acquisition of emails already exfiltrated by another actor: see the Intercept article Western Spy Agencies Secretly Rely on Hackers for Intel and Expertise, 4 February 2015.
This 13 September 2010 presentation from the NSA’s OTP VPN Exploitation Team explains the work of the division: see the Der Spiegel story Prying Eyes: Inside the NSA’s War on Internet Security, 28 December 2014.
These July 2009 documents provide a full list of the fibre-optic cables GCHQ had access to at that point, including details of location, bandwidth and corporate partners: see the Süddeutsche Zeitung article Snowden-Leaks: How Vodafone-Subsidiary Cable & Wireless Aided GCHQ’s Spying Efforts, 25 November 2014.
This internal NSA post from September 2006 describes the evolution of the European Security Operations Center and the focus of the US-German collaboration in signals intelligence: see the Der Spiegel article Terrorverdächtige: NSA nutzte Erkenntnisse aus Deutschland-Filiale für Tötungen, 15 June 2014.