Facebook says millions of users who thought they were sharing privately with their friends may have shared with everyone because of a software bug

As many as 14 million Facebook users who thought they were posting items that only their friends or smaller groups could see may have been posting that content publicly, the company said. According to Facebook, a software bug, which was live for 10 days in May, updated the audience for some user’s posts to “public” without any warning. Facebook typically lets users set the audiences who get to see posts; that setting is “sticky,” which means it remains the default setting until manually updated. Facebook was unclear about how many of the 14 million people may have posted to friends without realizing they were sharing that information publicly. The company said it will begin on June 7 to alert people who were impacted.