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I am working on SEO for a dental client, and I was looking at the external links for the main competitor. I noticed that a very large number of links were coming from other dental websites. When I looked more closely, I found that all of these websites had been created by one particular company specializing in dental websites. This company had hidden a directory on each client website with links to all their other client's websites. Is this something that can be reported? Is there anything I can do about it? Now I understand why I can't reach the number of external links that some of these other sites have! There are also many links coming from an online bookmark manager. I'm guessing these are accounts set up just to generate external links. How can anyone compete with that?