Proving to the newbs that you can use linux for almost 20 years and still not really understand the command line. Because you know what I would really do? Open the gui and click on the 'delete' button.
But you *could* delete a user called "Byron" and a user called "C" in a single command... (This, incidentally, is how Bumblebee once hosed everybody's systems: the upgrade script tried to clear out older versions by "rm -rf /etc/whatever/bumblebee" but actually "rm -rf /etc /whatever/bumblebee" which is not the same thing at all.)
Had a customer the other day that overwrote the whole /etc of a server with one from another server. Fortunately both servers were mostly the same, just UIDs, GIDs, ssh server keys and some symlinks for a secondary init system were bad. I recovered the server without reinstalling, mostly by removing unnecessary ini files from the init system and checking home folders for all users and groups in /etc/passwd and /etc/group, fixing the files manually.
