Comment 2 for bug 1526322

It's really confusing, it lead me to turn off numlock on my usb keyboard a few times this week which it returns created issues because a keypad is of no user when it's doesn't input numbers

That's a side effect from https://code.launchpad.net/~3v1n0/unity/lockscreen-num-lock-warning/+merge/276859 which has no attached bug nor rational :-/

it's also inconsistent with the greeter and other environment and was tried in the past and reverted because it's an unreliable hardware feature, see https://bugzilla.gnome.org/show_bug.cgi?id=662093 or https://bugs.launchpad.net/ubuntu/+source/gtk+3.0/+bug/841541