I noticed today when going to http://facebook.stackoverflow.com I am 301 Moved Permanently redirected to https://stackoverflow.com/questions/tagged/facebook*. Is the mini-site gone or is this just a bug?
We have removed the subsite. I am in the process of removing code for all subsites (it was the only instance in production) to greatly simplify many areas of our codebase.
facebook.stackoverflow.com was always an experiment, one we hoped would work out - but it didn't. The quality on the facebook tags didn't improve as a result of its presence, and the technical tradeoffs to support it were quite great. It causes a great deal of load on our systems when specific pages are hit because there's just no low-cost way to "filter" the site down to facebook-only tags.
After we weighed everything, it just wasn't worth keeping - it wasn't helping, caused confusion and it was causing technical hurt. I won't even go into the calls we get at the office from people locked out of their facebook accounts.