If you see this message on the Manual Actions page, it means that Google has detected a pattern of unnatural, artificial, deceptive, or manipulative links pointing to your site. Buying links or participating in link schemes in order to manipulate PageRank is a violation of Google's Webmaster Guidelines.
Google doesn't want to put any trust in links that are artificial or unnatural. However, because we realize that some links may be outside of your control, we are not taking action on your site's overall ranking. Instead, we have applied a targeted action to the unnatural links pointing to your site.
If you don't control the links pointing to your site, no action is required on your part. From Google's perspective, the links already won't count in ranking. However, if possible, you may wish to remove any artificial links to your site and, if you're able to get the artificial links removed, submit a reconsideration request. If we determine that the links to your site are no longer in violation of our guidelines, we’ll revoke the manual action.