Why all the outrage? The primary purpose of the GFDL is to free the content so that people can copy and modify it, specifically by preventing downstream content-modifiers from enforcing restrictions based on copyright law. It's not like Anthony is trying to prevent people from copying the stuff on McFly. On McFly, he has said he considers himself in compliance with our GFDL-related requirements. Even if he arguably doesn't follow every detail in the GFDL, in court he could certainly try to claim McFly satisfies a doctrine of substantial compliance. And anyway, where's the harm? Maybe if he were trying to pass himself off as the real thing, it would be worth pursuing more aggressive legal measures (I still think Wikipedia trademark registration is a more pressing issue to deal with than copyright).
Bottom line: McFly is a fork, and a pretty poor one. I know the thought of a fork gets some people's competitive juices going, but I don't think McFly is capable of seriously affecting Wikipedia's mind share. So far, it hasn't even really done much to articulate a justification for forking, it just went ahead and did it. Wikinfo/Internet-Encyclopedia at least has a raison d'etre. And neither of them comes close to Wikipedia in quality. So far, our history suggests that individual languages breaking away is a more serious concern for the project.
The GFDL is not so much a weapon for us to use against people who copy us--it's a defense for us to use if their stuff is good enough that we want to copy it back.
--Michael Snow