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.
I use ~/config/* to put directories named the same as system ones. I got used to it in BeOS and brought it to LFS when I finally accepted BeOS wasn’t doing what I needed anymore, kept doing it ever since.