On some UEFI-based systems, the old “rm -rf /” trick for destroying your system may do more than annihilate your software installation, it may also brick your machine. This is because it is possible to mount a virtual kernel filesystem that gives access to persistent UEFI configuration data read/write, and deleting this data makes it impossible for your machine to boot. <http://www.theregister.co.uk/2016/02/02/delete_efivars_linux/>