For security and privacy reasons, one might want to disable the media buttons
from the lock screen.

After raising https://bugs.kde.org/show_bug.cgi?id=384264 I understand that the
media buttons are embedded from inside the look and feel package, and openSUSE
provides its own here: plasma5-theme-openSUSE-42.1.1-22.1.noarch

The media buttons are defined here:
/usr/share/plasma/look-and-feel/org.openSUSE.desktop/contents/lockscreen/LockScreenUi.qml
line 183.

The idea would be to provide a look and feel specific setting (if technically
possible) to allow users to disable these media buttons.