XKeyscore

XKeyscore or XKEYSCORE (abbreviated as XKS) is a formerly secret computer system first used by the United States National Security Agency for searching and analyzing global Internet data, which it collects on a daily basis. The program has been shared with other spy agencies including the Australian Signals Directorate, Canada's Communications Security Establishment, New Zealand's Government Communications Security Bureau, Britain's Government Communications Headquarters and the German Bundesnachrichtendienst.

The program's purpose was publicly revealed in July 2013 by Edward Snowden in The Sydney Morning Herald and O Globo newspapers. The codename was already public knowledge because it is mentioned in earlier articles, and like many other codenames can also be seen in job postings, and in the online resumes of employees.

On July 3, 2014 excerpts of XKeyscore's source code were first published by German public broadcaster Norddeutscher Rundfunk, a member of ARD. A team of experts analyzed the source code. Recent articles mention that XKEYSCORE uses user metrics to flag certain data, such as race, sex, ethnicity, and geolocation.

XKeyscore is a complicated system and various authors have different interpretations of its actual capabilities. Edward Snowden and Glenn Greenwald explained XKeyscore as being a system which enables almost unlimited surveillance of anyone anywhere in the world, while the NSA has said that usage of the system is limited and restricted.

According to The Washington Post and national security reporter Marc Ambinder, XKeyscore is an NSA data-retrieval system which consists of a series of user interfaces, backend databases, servers and software that selects certain types of data and metadata that the NSA has already collected using other methods.

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