Not me, but a colleague questioned himself for a while over this one. He simply forgot a semicolon when doing some server maintenance:

sudo yum remove application1 sudo yum remove application2

This didn't just remove application1 and 2, it removed sudo and yum too. One slightly embarrassing call to the ops team later, we had to replace the box.

This, ladies and gentlemen, is why you should automate your server maintenance!