I had a contractor installing software last week. He was granted full sudo permissions despite having demonstrated a unique set of command line skills. Everything was going fine until I get a text from his manager saying the contractor couldn't SSH in this morning. Turns out he had gotten frustrated with some file/folder permissions in the directory where he was supposed to install the software package. So he simply ran `chmod -R 777 /*`

Needless to say that required a full restore from the previous night's backup since he hadn't snapshotted the VM before beginning his work. He was very angry that he had lost 2 days of work. I was very sympathetic...