The link for the league, http://stackexchange.com/leagues/week/facebook-stackoverflow points to a "Page Not Found" instead of either Stack Overflow league (which is still not the expected result) or Facebook Stack Overflow league (not sure if it has ever been implemented).
These are not the leagues you're looking for...
Seriously, we shouldn't have shown that link (just as we don't show the top % links in each profile) because the leagues don't make much sense. Given that reputation is not separate inside a subsite (it's the same reputation as on stackoverflow.com), we'd be effectively showing a league of "users with 200+ rep that asked or answered a facebook question"...but with reputation from everywhere on stackoverflow.com (not a value constrained to activity in facebook.stackoverflow.com).
The link will no longer appear on any subsites after the next build.