There's inspiration, then there's wholesale theft. When you realized that your copy came from somewhere else, you acknowledged that somebody else had done the work.

AUs and episode rewrites acknowledge from the get-go that they're taken from a particular source. I don't think you could get away with selling it, but in the world of fanfic, I don't see the wrong.

Personally, I despise CC and her ilk because they are thieves. CC steals the words and ideas that someone else put together and calls them her own. How is this not theft?

Has no one learned from the experience of that plagiarizing Chick-Lit girl a few months back?