If I'm understanding correctly, you're saying that you made a list of what you have in your collection and gave it to a member with a low post count, and that member then went behind your back and gave your list to other people who are now coming to you asking about your collection? I'm confused where Yahoo auctions comes into play here.
I'm equally confused. Since what your trying to express seems a little complicated, maybe you want to try adding what you said in your home language. I'm sure someone can translate and make more sense of it.