[DrStalker]

From memory setting a UID to 0 was a way to effectively have multiple root accounts on a system. sudo is a much better solution to the same problem so using uid 0 in this manner is not something I expect to see on any modern unix/linux system.

[dredmorbius]

"shutdown" or "reboot" as a UID=0 user with shell set to "/sbin/shutdown" or "/sbin/reboot" and a specific password is still occasionally found. Log in as that to shut down or reboot system.