Enlarge / Facebook Lite users made up the majority of Facebook accounts exposed internally by plaintext password logging, according to a Facebook spokesperson. Facebook has mined a lot of data about its users over the years—relationships, political leanings, and even phone call logs. And now it appears Facebook may have inadvertently extracted another bit of critical information: users' login credentials, stored unencrypted on Facebook's servers and accessible to Facebook employees. Brian Krebs reports that hundreds of millions of Facebook users had their credentials logged in plain text by various applications written by Facebook employees.