An anonymous reader writes: Since the NSA's phone metadata program broke last summer, politicians have trivialized the privacy implications. It's 'just metadata,' Dianne Feinstein and others have repeatedly emphasized. That view is no longer tenable: Stanford researchers crowdsourced phone metadata from real users, and easily identified calls to 'Alcoholics Anonymous, gun stores, NARAL Pro-Choice, labor unions, divorce lawyers, sexually transmitted disease clinics, a Canadian import pharmacy, strip clubs, and much more.' Looking at patterns in call metadata, they correctly diagnosed a cardiac condition and outed an assault rifle owner. 'Reasonable minds can disagree about the policy and legal constraints,' the authors conclude. 'The science, however, is clear: phone metadata is highly sensitive.'