Facebook Stored Hundreds of Millions of User Passwords in Plain Text for Years
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.
[…]
The Facebook source said the investigation so far indicates between 200 million and 600 million Facebook users may have had their account passwords stored in plain text and searchable by more than 20,000 Facebook employees. The source said Facebook is still trying to determine how many passwords were exposed and for how long, but so far the inquiry has uncovered archives with plain text user passwords in them dating back to 2012.
My Facebook insider said access logs showed some 2,000 engineers or developers made approximately nine million internal queries for data elements that contained plain text user passwords.