The notion of online privacy has been greatly diminished in recent years, and just this week two new studies confirm what to many minds is already a dismal picture.First, a study reported on Monday by Stanford University found that smartphone metadata — information about calls and text messages, such as time and length — can reveal a surprising amount of personal detail.To investigate their topic, the researchers built an Android app and used it to retrieve the metadata about previous calls and text messages — the numbers, times, and lengths of communications — from more than 800 volunteers’ smartphone logs. In total, participants provided records of more than 250,000 calls and 1.2 million texts.[ Don’t miss a thing! Sign up for CIO.com newsletters ]The researchers then used a combination of automated and manual processes to understand just what’s being revealed. What they found was that it’s possible to infer a lot more than you might think.A person who places multiple calls to a cardiologist, a local drug store, and a cardiac arrhythmia monitoring device hotline likely suffers from cardiac arrhythmia, for example. Based on frequent calls to a local firearms dealer that prominently advertises AR semiautomatic rifles and to the customer support hotline of a major manufacturer that produces them, it’s logical to conclude that another likely owns such a weapon.The researchers set out to fill what they consider knowledge gaps within the National Security Agency’s current phone metadata program. Currently, U.S. law gives more privacy protections to call content and makes it easier for government agencies to obtain metadata, in part because policymakers assume that it shouldn’t be possible to infer specific sensitive details about people based on metadata alone.