By entering your Facebook password, the M3 Facebook app will verify the password with Facebook, but not retain it. Once you log in via the Facebook login button on the left sidebar, you will be able to make comments without having to input your email, website and name each time.
This Facebook API is housed and programmed by Facebook, not M3. It is governed by your settings on Facebook. There are no controls to it on M3 for you as a user or M3 as administrator.
The API does not pull anything from Facebook except your login cookie and your profile picture. It will check to see if you are logged into Facebook. When you like or share a post to Facebook, Facebook will supply your profile picture beside the “like” button at the top of the screen according to the privacy settings you have chosen on Facebook.
WordPress users must input their WordPress user name to complete registration and sync with Gravatar. Facebook does not provide profile picture sync for comments.