The act of bad-mouthing someone via instant message, only to find out that you just instant messaged that person, instead of the intended audience.
Instant message Conversation:
Bob: Hey Melissa, would you rather kiss Nashe or eat a sand sandwich
Nashe: What are you talking about? What is your question?
Bob: Oh crap, nevermind
Nashe: Oh shit, I've just been Nashe'd