Defenders of the NSA's mass spying have lost an important talking point: that the erosion of our privacy and associational rights is justified given the focus of surveillance efforts on combating terrorism and protecting the national security. That argument has always been dubious for a number of reasons. But after a November 2015 ruling by the secretive Foreign Intelligence Surveillance Court (FISC) was unsealed last week, it's lost another chunk of its credibility. The ruling confirms that NSA's warrantless spying has been formally approved for use in general criminal investigations. The national security justification has been entirely blown. Read more.