One of a prior boss's war stories was that our CTO once logged in the main production server and did a 'rm -rf '. This is back when it'd actually delete everything. This was also back before most companies had back up prod servers.

From what I understand, it was a long weekend bringing that server up from tape backups.

The funniest thing to me wasn't that it happened. It was who it happened to. The CTO has created (and was granted patents for) multiple utilities still used very frequently in nix environments today.