The expression you make when someone pisses you off on online chat.
Chatting on messenger to my buddy, when he says something that really annoyed me, therefore WC, the saying of "WHATEVER" and then slamming your laptop lid down, hence the click, or click to close the Instant Message. - WC - Whatever Click
Fred: You are a jerk
Bob: You are so Rude! W C!
Instant messenger goes off!