I find this Italian yiffy-themed furry forum yesterday: http://yiff.forumcommunity.net/

There's art from many artists who're in FA, I recommend to check it out and if you find your art there and want it to be removed, contact their host Forumcommunity because the forum don't even have DNP list and some of the pics are posted by the moderators or even admins.

Notice that you don't need to register there in order to see the main yiff areas where the pics are.

It shouldn't be hard to get that forum down because Forumcommunity's TOS prohibits copyright violations like art theft:
2.6 It is also not allowed:
- to publish and/or require serial codes for commercial software;
- to publish and/or request links to warez sites and containing material that violates copyright laws and copyright.

Spread the word!

Btw, there's even Sexyfur stuff and I'll inform Bernal about it.