Remotely lock KDE session

To remotely lock your KDE session, login via ssh and execute following command:

for KDE 4.9:
DISPLAY=:0 /usr/lib/kde4/libexec/kscreenlocker --forcelock >/dev/null 2>&1 &

for KDE 4.10:
DISPLAY=:0 /usr/lib/kde4/libexec/kscreenlocker_greet >/dev/null 2>&1 &