Hmm, I don't see "Do you have to destroy another email account in order to set it up?" on the FAQ list. I suppose, arguably, a user would be impelled to use the service by witnessing the destruction of an account near and dear to them, perhaps enough to split their soul...
IANAL but with my 10 mins of googling I've found the following:
* Items/characters cannot be trademarked unless they are the source of goods or services (so therefore this service would have the right whereas JK. Rowling et al wouldn't) [1]
* Items/characters are copyrighted when featured in a copyrighted piece of fiction (which Horcruxes are). [1]
* JK Rowling et al are crazy litigious [2][3]
* JK seems to endorse/praise fan collections of stuff, but the team come down hard on people trying to sell that commercially. [2] That does, however, seem to be for publishing books eg. fan fact books.