I am the webmaster of Cinderella.de. As Princo pointed out already our website was hacked and was hosting a split until yesterday, when I received a mail message about this issue (I assume that this was sent by Princo).
Because our site is fairly high ranked in Google the results show up earlier than those of your own blog. I contacted google and asked them to remove the pages from their index and caches.
I am sorry that this happened to your content. If this ever happens again you should notify the webmaster of the offending site immediately. A simple email usually suffices to shut down the splog and also helps to fix security issues at the hacked sites.