XKeyscore

XKeyscore (XKEYSCORE or XKS) is a classified computer system used by the United States National Security Agency (NSA) for searching and analyzing global Internet data, which it collects in real time. The NSA has shared XKeyscore with other intelligence agencies, including the Australian Signals Directorate, Canada's Communications Security Establishment, New Zealand's Government Communications Security Bureau, Britain's Government Communications Headquarters, Japan's Defense Intelligence Headquarters, Germany's Bundesnachrichtendienst, and the Danish Defense Intelligence Service, the latter of which proceeded to use it to spy on the UK, Germany, and other key allies for the US.

In July 2013, Edward Snowden publicly revealed the program's purpose and use by the NSA in The Sydney Morning Herald and O Globo newspapers. The code name was already public knowledge because it was mentioned in earlier articles, and, like many other code names, it appears in job postings and online résumés of employees.