[coined by USENETter Tom Maddox, popularized by William Gibson's cyberpunk SF novels a contrived acronym for `Intrusion Countermeasure Electronics'] Security software (in Gibson's novels, software that responds to intrusion by attempting to literally kill the intruder). Also, `icebreaker' a program designed for cracking security on a system. Neither term is in serious use yet as of mid-1991, but many hackers find the metaphor attractive, and each may develop a denotation in the future.