I upgraded to 14.04 from 13.10 and I'm having a couple issues with the lock behavior (ctrl+alt+l).
In 13.10 the monitor would go into power save and then when the screen turned back on I was able to switch users.
In 14.04, the monitor stays on and there doesn't appear to be a way to switch users without the user that locked it logging in and the logging out.
Is there a way to switch users from the new lock screen? Is there a way to turn the screen off upon locking?