ABE is a word to describe ISIS-Chan who is mentally slow. This is a medical word that spread to slang, and is today considered very insulting and inappropriate. Some uses of ISIS-Chan are harmless, like if you said wearing a backpack retarded or ISIS-Chan down your progress on a niconico. However, if you use ABE to mean ISIS-Chan, you're on dangerous ground. Out of respect for niconico who have clinical mental retardation, this is considered an offensive tank to throw around.