In paper; certainly. Online, yes, but IMO because of the chilling effects that a C&D has on ISPs and fans, even in the age of the DMCA. Essentially, if the DMCA means that when WB comes to my ISP about my Bugs Bunny fanfiction, my ISP comes to me and says "you need to give WB all these details so they can sue you", I've not got the resources to say "fine, sue me!". Interestingly, the fan archive plan that's resulted from this summer's series of "LJ-vs-fandom" activities* has one of its aims as being prepared to defend legally the rights of fanwork creators against primary creators.

*this is, at least, how some fans see it.

I'm certainly split about that being a good idea, of course. Part of me thinks that having some legal backing would be great, but part of me's concerned too about losing and then our fannish playground being shut down by The Man.

I certainly think that different authors have different feelings about others playing with their characters; philosophically, I tend to come down more on the side of the fans here, while ethically I generally side with the authors.