I once saw Elizabeth Bear commenting, several years ago, that at least one of her published short stories was fanfic-with-filed-off-serial-numbers. (I don't regularly read her journal, so I have no idea if this is something she's mentioned/done more than once.)

I can't recall if she mentioned the specific fandom at the time, but based on comments I've since seem from readers, I believe it was something related The Man from U.N.C.L.E.