From the article "The Times reported that the Justice Department permitted the NSA to monitor only addresses and "cybersignatures," patterns tied to computer intrusions, that it could link to foreign governments. But the documents showed that the spy agency sought to target hackers even when it could not establish links to foreign countries."
The NSA is part of the military. They are part of the DoD under the Pentagon. That makes it a military organization having authority over the civilian population.
It's a violation of the constitution if you don't have a warrant, period!http://www.reuters.com/article/2015/06/04/us-usa-security-nsa-idUSKBN0OK23Q20150604