In one of the documents, agency personnel are instructed to remove details and substitute more generic language in reports to the Justice Department and the Office of the Director of National Intelligence.
The Post cited a 2008 example of the interception of a 'large number' of calls placed from Washington when a programming error confused U.S. area code 202 for 20, the international dialing code for Egypt, according to a 'quality assurance' review that was not distributed to the NSA's oversight staff.
In what the Post said appeared to be one of the most serious violations, the NSA diverted large volumes of international data passing through fiber-optic cables in the United States into a repository where the material could be stored temporarily for processing and selection.
The operation collected and commingled U.S. and foreign emails, the Post said, citing a top-secret internal NSA newsletter. NSA lawyers told the Foreign Intelligence Surveillance Court that the agency could not practicably filter out the communications of Americans.
In October 2011, months after the program got underway, the court ruled that the collection effort was unconstitutional.
The New York Times reported that 1,904 of the incidents appeared to be 'roamers' - foreign nationals whose cell phones were being wiretapped without warrants who then came to the U.S.
