The US National Security Agency for years collected masses of raw data on the email and internet traffic of US citizens and residents, the website of Britain's Guardian newspaper has reported, bringing to light another mass surveillance program that affected Americans.
Citing a top-secret draft report prepared in 2009 by NSA's inspector general, the Guardian said that the collection of the raw internet traffic information - described as "bulk internet metadata" - began shortly after the attacks of September 11, 2001.
Initially the program collected information in which one party was outside the United States or communications between known foreigners, but expanded in 2007.
The paper said the internet "metadata" which the NSA collected comprised the addresses to and from which messages were sent, including IP addresses which could show a person's physical location.
The latest Guardian revelations appear to show that the NSA collected the same kind of raw internet traffic data among people inside the United States as it collects on telephone users.
The Guardian also previously published secret documents about an NSA program called Prism which involved NSA being able to search the content of traffic sent through US internet companies by foreign intelligence subjects. The paper's latest revelations do not discuss the searching or examination of email content.
The Guardian said that the NSA internet metadata collection initially began under a controversial warrantless wiretapping program authorised by the administration of President George W Bush, but was later authorised by the secretive Foreign Intelligence Surveillance Court.
The Guardian quoted Shawn Turner, chief spokesman for the US Director of National Intelligence, saying that the collection program, which continued after Barack Obama became president, was terminated in 2011 "for operational and resource reasons and has not been re-started."
Turner added: "The program was discontinued by the Executive branch as the result of an interagency review."
An official in the intelligence director's office confirmed the accuracy of Turner's quote.
However, the Guardian said that it had seen other secret NSA papers which suggested that some collection of Americans' online records continued today.
Previously, citing documents provided by former NSA contractor Edward Snowden, the Guardian reported that NSA also had been authorised by the FISA court to collect masses of similar "metadata" charting traffic between phone numbers which called each other both within the United States and between the United States and foreign countries.
The existence of such an NSA program was subsequently acknowledged by US officials.
The Guardian's latest story said that when NSA first started collecting internet metadata in the wake of the September 11 attacks, the agency could only collect such material in cases where "at least one communicant" was located outside the United States "or for which no communicant was known to be a citizen of the United States."
However, the Guardian printed what it said was a 2007 US Justice Department memo, classified secret, which it said indicated that NSA later got authority to "analyse communications metadata associated with United States persons and persons believed to be in the United States."