@doctorow "Facebook also allowed Spotify, Netflix and the Royal Bank of Canada to read, write and delete users’ private messages, and to see all participants on a thread ..."
https://www.techdirt.com/articles/20181219/10370941268/facebooks-latest-privacy-screwup-shows-how-facebooks-worst-enemy-is-still-facebook.shtml
This goes beyond surveillance (as if that wasn't bad enough), interfering with whether people receive private messages is manipulating their relationships.