The National Security Agency built a "Google-like" search engine to give domestic and international government agencies access to details of billions of calls, texts and instant messages sent by millions of people, according to The Intercept.

The search engine, called ICReach, had behind it roughly 850 billion pieces of metadata in 2007 on calls made largely but not exclusively by foreign nationals, the report said.

Metadata is the data the surrounds a communication but not the contents of the message or telephone call itself. In the case of ICReach, the program includes the date, time and duration of calls, the number of the caller and destination, and, in the case of a mobile telephone, the unique IMEI number of the handset being used, according to a document published earlier this year by the American Civil Liberties Union.

Additional documents published by The Intercept said it also includes details of the cellular network and base station being used, the latitude and longitude in the case of an Inmarsat satellite call, an email address in the case of an Internet message and a chat handle in the case of an instant message.

While the contents of the communications are not revealed, access to enough metadata on an individual's personal communications can be used to reveal certain traits, preferences or details about the person.

The NSA apparently controlled access to ICReach but extended it to its equivalent agency in the U.K., the Government Communications Headquarters, according to a 2007 document. At the time, the system was also planned to be extended to intelligence agencies in Canada, Australia, New Zealand and to the U.S. Central Intelligence Agency. Through the CIA, the information would also be available to the FBI, Drug Enforcement Agency and Defense Intelligence Agency.

Together, roughly 1,000 analysts at 23 U.S. government agencies had access in 2010.

Martyn Williams covers mobile telecoms, Silicon Valley and general technology breaking news for The IDG News Service. Follow Martyn on Twitter at @martyn_williams. Martyn's e-mail address is martyn_williams@idg.com