https://krebsonsecurity.com/2019/03/facebook-stored-hundreds-of-millions-of-u...
и официальное подтверждение
https://newsroom.fb.com/news/2019/03/keeping-passwords-secure/
Для Ъ:
Facebook is probing a series of security failures in which employees built applications that logged unencrypted password data for Facebook users and stored it in plain text on internal company servers. That’s according to a senior Facebook employee who is familiar with the investigation and who spoke on condition of anonymity because they were not authorized to speak to the press.
