Comment by seoulbigchris

This was back in the early 90s. Our company used DOS and Windows machines for the most part, but we had a brand new Sun workstation for an advanced PCB layout tool (Cadence?). One day my buddy was working on the Sun, and wanted to make a backup before starting a new task. He did something like `mkdir backup` and `cp -r * backup`. It started churning away, and we went to lunch. Came back from lunch, and the machine was frozen. It took us a few moments before we realized what went wrong. He had copied recursively forever, or rather, until there was no more free disk space. In our defense, we were new to Unix and still learning.