How to exclude users from GDM login screen?
Posted on In QAHow to exclude users from appearing in the GDM login screen of Gnome 3?
There is a long-time bug related to this ( https://bugzilla.redhat.com/show_bug.cgi?id=723708 ) which causes that the /etc/gdm/custom.conf has no effect.
The closes workaround I find working on Fedora 20 is to totally disable listing of users (run as root):
cat > /etc/dconf/db/gdm.d/01-mysettings <<EOF
[org/gnome/login-screen]
disable-user-list=true
EOF
rm /etc/dconf/db/gdm
dconf update
Reference: https://ask.fedoraproject.org/en/question/9875/how-do-i-disable-user-list-in-gdm/
