the correct syntax is: sudo -u#-1 whoami [sudo] password for john: root The "#" is required to identify the string that follows as a UID, vs a username.

A little know and highly secret NSA monitoring system, codenamed "Losira"....

See how that works? They've created the requirement for additional investigation, thus ensuring job security - at least until the zombie apocalypse....at which point, they'll go to the *real* safest location.