The action of being in a chat room, observing and silently judging all the people involved in the chat discussion(s) at a certain point in time without saying a word.
Dude #1: Dude, and then he said some weird crap I didn't even know existed.
Dude #2: You were SFDing the entire thing, weren't you?
Dude #2: You were SFDing the entire thing, weren't you?
by John Baine January 24, 2014