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.

