Fugitive former United States National Security Agency employee Edward Snowden has leaked further documents on a mass surveillance program that he claims enables American analysts to wiretap anyone in the world.
Called X-Keyscore, the program is the widest reaching system to develop intelligence from computer networks, according to NSA training material slides given to the Guardian by Snowden.
A wide variety of information is available to analysts through X-Keyscore. This ranges from contents of emails to browser history and other online activity.
Real time activities such as Facebook chats can also be captured by X-Keyscore, the NSA documents purport. However, while X-Keyscore can be used to spy on unencrypted hypertext transport protocol (HTTP) internet traffic according to the slides, it is unclear if it can be used to intercept encrypted secure sockets layer (SSL or HTTPS) data as well.
X-Keyscore is thought to be run by the NSA and the Australian Defence Signals Directorate (DSD) as well as the New Zealand Government Communications Security Bureau (GCSB), with spy agencies from Canada and the United Kingdom also participating.
An earlier leak by Snowden indicates the program is run from bases in Australia and New Zealand with over 700 servers processing the data.
According to the NSA documents obtained by the Guardian, X-Keyscore intelligence led to 300 terrorists being captured by 2008.
A vast amount of data is accessible through X-Keyscore. By 2012, at least 41 billion records were collected and stored in X-Keyscore for a single 30-day period according to the NSA documents, with another one to two billion records being added every day.
X-Keyscore is used as part of the NSA's lawful foreign signals intelligence collection system, the NSA said in a statement.
It said access to the data was only provided to personnel who required it for their assigned tasks.
"Allegations of widespread, unchecked analyst access to NSA collection data are simply not true."