https://thenextweb.com/facebook/2018/06/08/facebooks-latest-privacy-blunder-made-private-posts-public-for-14-million-users/

Facebook is again at the center of a privacy controversy after revealing today that it had been inadvertently sharing private posts publicly for some 14 million users.

When attempting to test a feature on users’ profiles, developers introduced a bug that exposed the posts of some individuals who thought they were posting privately, Facebook revealed.