Added a superimposed padlock to the blurred screen

I added a superimposed padlock to make the screen less ambiguous and give your eyes something to focus on when you look at it (this was causing me a lot of eye strain). Maybe this would be best as a command-line toggleable option?
Ah, ok, it is fine, but then you'd probably want to use $TMPDIR instead of /tmp prefix in the path I would think.