When we can start fining you for your mistakes, when developers can start getting fired for any mistakes immediately.
I don't care about Facebook, but storing user passwords is the plain is not "privacy violation" without the password they still have access to all your data. storing user passwords by logging it is stupid amateur security mistake.
I can understand if Facebook stored the password and used it to access your other accounts with permissions to invite users then sure fine em. But mistakes are mistakes, they owned up to it.