screaming tty

screaming tty n.  [UNIX] A terminal line which spews an infinite
   number of random characters at the operating system.  This can
   happen if the terminal is either disconnected or connected to a
   powered-off terminal but still enabled for login; misconfiguration,
   misimplementation, or simple bad luck can start such a terminal
   screaming.  A screaming tty or two can seriously degrade the
   performance of a vanilla UNIX system; the arriving "characters"
   are treated as userid/password pairs and tested as such.  The UNIX
   password encryption algorithm is designed to be computationally
   intensive in order to foil brute-force crack attacks, so although
   none of the logins succeeds; the overhead of rejecting them all can
   be substantial.