Ability to hide current user/ list of users from lock screen

[mmseng]

As a privacy feature it would be desirable to have a configurable option to hide the current/known users from the lock screen.

Because so many people confuse these, I will state up front that I am in fact referring to the lock screen, and not the login screen. The login screen already has plenty of configurability.

This was a feature request way back in 2013 (source), but it gained no traction because it was deemed a novel feature for any OS. However as far as I can tell, this feature was available in Windows as far back as 2003, and possibly earlier, in the form of the DontDisplayLockedUserId registry setting and the Interactive logon: Display user information when the session is locked group policy, and is quite popular in multi-user environments such as schools.

As a side note, the lock screen could use more configurability in general. From what I can tell, there is still no official or reliable way to provide a unique background image for it, distinct from the current user's desktop background image.