luser

luser n.  /loo'zr/ A {user}; esp. one who is also a
   {loser}.  ({luser} and {loser} are pronounced
   identically.)  This word was coined around 1975 at MIT.  Under
   ITS, when you first walked up to a terminal at MIT and typed
   Control-Z to get the computer's attention, it printed out some
   status information, including how many people were already using
   the computer; it might print "14 users", for example.  Someone
   thought it would be a great joke to patch the system to print "14
   losers" instead.  There ensued a great controversy, as some of the
   users didn't particularly want to be called losers to their faces
   every time they used the computer.  For a while several hackers
   struggled covertly, each changing the message behind the back of
   the others; any time you logged into the computer it was even money
   whether it would say "users" or "losers".  Finally, someone
   tried the compromise "lusers", and it stuck.  Later one of the
   ITS machines supported `luser' as a request-for-help command.
   ITS died the death in mid-1990, except as a museum piece; the usage
   lives on, however, and the term `luser' is often seen in program
   comments.