sorcerer's apprentice mode
(From Johann Wolfgang von Goethe's "Der Zauberlehrling", via the Walt Disney film "Fantasia") A bug in a protocol where, under some circumstances, the receipt of a message causes multiple messages to be sent, each of which, when received, triggers the same bug. Used especially of such behaviour caused by bounce message loops in electronic mail software.
Compare broadcast storm, network meltdown, software laser, ARMM.