Quote: Warning: When switching users using a display manager such as GDM or LightDM, XScreenSaver will not lock the original session - it can be accessed without a password simply by switching TTY's to the session in question. If you are using LightDM, as a workaround, install light-locker and run it alongside XscreenSaver. Alternatively, use a different screen locking program altogether - see List of applications/Security#Screen lockers.

Quote:Session failure

Symptoms include:

    The mouse is an X and/or does not appear at all;