https://www.theregister.co.uk/2018/06/07/facebook_posts_forced_public/

Facebook is having to douse yet another privacy blaze – as the social network admitted to inadvertently setting some of its addicts' private posts to public, meaning anyone could read them.

The web goliath said that aout 14 million people were affected by a bug that, for a nine-day span between May 18 and 27, caused profile posts to be set as public by default, allowing any Tom, Dick or Harriet to view the material.