The warrant did not give the power to rummage through the journalist's files... there is no indication of why all this information needed to be seized
From: The Guardian article Federal agents accused of unwarranted search through journalist's computer 29 January 2014 http://www.theguardian.com/world/2014/jan/29/matthew-keys-investigation-hacker-computer-search
Federal agents accused of unwarranted search through journalist's computer