It happend to me just now, using Ubuntu 14.04LTS.
I left my PC for 10 minutes, and when I got back screen was black. I moved my mouse and screen become active and it displayed Ubuntu lock screen with my laucnher, panel and desktop showing also.
Same thing is when I lock PC myself.
It happend to me just now, using Ubuntu 14.04LTS.
I left my PC for 10 minutes, and when I got back screen was black. I moved my mouse and screen become active and it displayed Ubuntu lock screen with my laucnher, panel and desktop showing also.
Same thing is when I lock PC myself.