I worked in IT at a hospital where leaving workstations unlocked is a big no-no. Any time my coworkers did so it was standard procedure to do the following:

1) Change all their desktop icons to target shutdown.exe (I had a script on the shared drive for this).

2) Screenshot the desktop, rotate it 180 in paint then set it to the desktop background.

3) Select all the icons on their destop and hide them.

4) Close all the open applications.

5) Hide the task bar.

6) Hit CTRL+ALT+Up Arrow to enter “projector mode” and get the inverted desktop screenshot back to “normal” but completely screwing up mouse movement.

7) Turn the monitor off.

8) Unplug the keyboard and mouse.

Always fun to watch them struggle through the process in reverse just to end up shutting down when trying to open outlook.