When I was in School we had one Computer room where the PC's were the school used to 'teach stuff about pcs' (mostly office and some Maya). These where connected to another via the network and reset to a predefined state Everytime they were rebooted.

Since we were somehow able to get into the room during breaks between the lessons we obviously abused the room and played Minecraft in there but since the machines reset each reboot there was not much progress. Also there was no Java installed, so we needed to install that as well (that can take ages on old, school machines.).

Since the machines were connected via the school network I found out how to reboot or shutdown the other machines remotely. That was really funny for me and a friend who quickly found that Minecraft is too boring. We were just constantly rebooting the PC's the others were just launching Minecraft on and thus resetting the whole Java and Minecraft installation.

Got a lot of angry curses but nothing serious happened afterwards. Was the first I felt really badass on the computer tho.