I think filing a counterclaim is a wise move according to what little I know about the legal side of things. @PoiSonSonic: In any case, I don't get why someone would ever seriously think of monetizing the work of someone else. I'm not sure if I'm misunderstanding you but you talk about the creator being at fault for not monetizing his own work adequately and call it capitalism when you take the opportunity to do it. Now then, what prevents you from making a deal with the aforementioned creator? If it's really true that you can make something great out of a given work you just need to convince the other party of that. I'm assuming many things but I still think this is worth considering in most, if not all, cases.