This 15 December 2003 post from the internal NSA newsletter SIDToday discusses plans for the agency’s operations at the Athens Olympics the following year: see the Intercept article A Death in Athens: Did a Rogue NSA Operation Cause the Death of a Greek Telecom Employee?, 29 September 2015.
This 26-page NSA document, originally presented at 2012’s Five Eyes SIGDEV conference, gives a detailed overview of the agency’s information gathering on world mobile phone networks. Some intercepted technical and contact details have been redacted: see the Intercept article
Operation Auroragold: How the NSA Hacks Cellphone Networks Worldwide, 4 December 2014.
This undated NSA document gives updates on various activities of the US-German Joint SIGINT Activity during 2007: see the Der Spiegel article Snowden-Dokumente: Hier sitzt die NSA in Deutschland, 18 June 2014.
This Special Source Operations presentation describes the NSA’s problems with overcollection of data from email address books and buddy lists: see the Washington Post article NSA collects millions of e-mail address books globally, 14 October 2013.