Second, it appears that you are trying to gear up for a legal case. I strongly recommend against this action. Litigation is never cheap and is seldom fun.
I would recommend contacting the site where the content is being posted. If you can prove that you were not the one who created the fake ad, many of these sites will remove the content in question. That being said, once it is on the Internet, it will most likely be there forever in some form or another (think Google Cache).
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