Why defending programs in the game of Android Netrunner are called Ice? Is it an acronym? Or something else?
Ice stands for "intrusion countermeasures electronics", a term popularized by William Gibson.
— Android Netrunner Comprehensive Unofficial Rules Wiki entry for Ice
According to the original Netrunner rulebook (and as recorded in the Wiki ):
The corps in Netrunner view it as an acronym for Intrusion Countermeasure Electronics.
The runners view it as an acronym for Insidious Cortical Electrocution.
The original rulebook included it in the corp (runner) glossary thus:
Ice: A program that protects our data forts from intrusion. An acronym for "intrusion countermeasures electronics." (An acronym for "insidious cortical electrocution.")