From Encyclopedia Dramatica
JFC is internet slang for Jesus Fucking Christ. It's a combination of the common exclamative Jesus Christ—used to indicate shock or facepalm—with the adjunct fucking to demonstrate that you mean serious business.
- Prima: I think new user Sephiroth1337 is just a sock of 1337Sephiroth.
- Secunda: Not everyone is a sock, JFC.