When I worked at SpaceX, lots of software folk used an internal IRC server. One time I created a chatbot that would execute arbitrary python commands on my workstation. Knowing that coworkers would maliciously try to pwn my computer, I ran it in a chroot with very restricted permissions. It took about 20 minutes for someone to figure out how to fork bomb it hard enough to lock up my system.

Another time as a team building activity, we were using mission control and backup mission control to play a multiplayer space ship bridge simulator game. My team was winning, up until our terminals started failing. Someone on the other team had credentials to the IT system, and was remotely rebooting them.