[iansales]

I wouldn't worry about it. I've put stories through online writing workshops, and I've never heard of anyone passing of other work as their own. Of the top of my head, the only recent cases I can think of are: a vanity-published fantasy "ghostwritten" by con-artist-posing-as-agent Christopher Hill for some gullible woman, and a mainstream novel by a US student that was quickly withdrawn when it was shown it had been plagiarised.