COURT RULING

Earlier this week, leaders of the US Senate Intelligence Committee said they were working on legislation that would tighten oversight of federal electronic eavesdropping programs. Support for such changes has been growing since Snowden leaked information in June that the government collects far more Internet and telephone data than previously known.

The Times said that an NSA spokeswoman, asked about the analyses of Americans' data, said, "All data queries must include a foreign intelligence justification, period." It quoted her as saying: "All of NSA's work has a foreign intelligence purpose."

She said the policy change disclosed in the latest revelations was based on a 1979 Supreme Court ruling that Americans could have no expectation of privacy about what numbers they had called.

The Times quoted her as saying that, based on that ruling, the Justice Department and the Pentagon decided that it was permissible to create contact chains using Americans' "metadata," which includes the timing, location and other details of calls and emails, but not their content. The agency is not required to seek warrants for the analyses from the Foreign Intelligence Surveillance Court.

NSA officials declined to identify which phone and email databases were used to create the social network diagrams, and the documents provided by Snowden do not specify them, the paper said.

It said the NSA did say that the large database of Americans' domestic phone call records, which was revealed by Snowden in June and caused alarm in Washington, was excluded.

The Times said that while concerns in the United States since Snowden's revelations had largely focused on the scope of the agency's collection of the private data of Americans and the potential for abuse, the new documents provided a rare window into what the agency actually did with the information it gathers.