Hi, Check out this article on Intellectual Property Law on our Business Law Advisor blog.

If the websites that copied your material included your name as author, you probably can't sue them for copyright infringement. I have discovered a number of my articles posted on various web sites and in newsletters and magazines, but in each case my name, and often my business name, are included as the author. In that case, copyright infringement has not occurred. If indeed your material is being copied without being attributed to you, you may be able to have the material removed from the web sites by sending a strongly worded letter. I had that happen once. The person was pulling material from magazines and web sites and giving the impression it was her own. In my research I learned that I needed to notify the person by registered letter with return receipt requested that she had to remove the material by a certain date or I would have my attorney contact her. That was enough to take care of the situation. If you send a letter, be sure to inform the person that copyright infringement is a federal offense. That in itself may be enough to deter someone. For copyright infringement to occur, the person must reprint your exact written words. Ideas cannot be copyrighted. Therefore, if the person read your material and it inspired them to write an article on the same topic, they are guilty only of a lack of creativity, not of copyright infringement. You may want to do some reading on copyright law so you know what is acceptable and what isn't.

Have you consulted an intellectual property lawyer about your concerns? Perhaps he can give you more relevant legal advice with this matter.