I accidentally untarred archive intended to be extracted in root directory, which among others included some files for /etc directory.
I went on to rm -rv ~/etc, but I quickly typed rm -rv /etc instead, and hit enter, while using a root account.
OOOOOOOOOOOF!!
One trick I use, because I’m SUPER paranoid about this, is to mv things I intend to delete to /tmp, or make /tmp/trash or something.
That way, I can move it back if I have a “WHAT HAVE I DONE!?” moment, or it just deletes itself upon reboot.