NSA sifting more data from Americans than thought to hunt for links to intel targets

The N.S.A. is not just intercepting the communications of Americans who are in direct contact with foreigners targeted overseas, a practice that government officials have openly acknowledged. It is also casting a far wider net for people who cite information linked to those foreigners, like a little used e-mail address, according to a senior intelligence official.

While it has long been known that the agency conducts extensive computer searches of data it vacuums up overseas, that it is systematically searching — without warrants — through the contents of Americans’ communications that cross the border reveals more about the scale of its secret operations…

Government officials say the cross-border surveillance was authorized by a 2008 law, the FISA Amendments Act, in which Congress approved eavesdropping on domestic soil without warrants as long as the “target” was a noncitizen abroad. Voice communications are not included in that surveillance, the senior official said.