According to classified documents obtained by former security contractor Edward Snowden, the National Security Agency in 2012 expanded the scope of its surveillance to include Americans' cross-border Internet traffic, in an attempt to catch computer hackers operating in foreign countries.
But the documents, which were shared with the The New York Times and ProPublica, show that the NSA went after hackers even if it was unable to show that their attacks were coming from abroad. And "a lot" of data, from communications to personal information, was scooped up in the process, according to one document.
The power to expand the scope of NSA spying came from two secret Justice Department memos that allowed the intelligence agency to begin intercepting traffic passing through the Internet in the U.S. without a warrant.
The revelation comes days after President Obama signed into law the USA Freedom Act, a long-debated bill that curtails some of the NSA's powers authorized by the Patriot Act. The bill did not address warrantless searches.
The Justice Department memos piggybacked on a decision from a secret surveillance court that allowed the NSA to use the program to spy on foreign governments. But the agency complained that often it's hard to pin an intrusion on a foreign power because of the ease with which hackers can mask their location or cover their tracks. The NSA was given approval in 2012 to use the program to catch generally "malicious cyberactivity."