Google has serious partiality on some sites. This site movingscam.com openly sells links on their site. They have excellent ranking and never penalized for selling links. But some sites even if you have one suspicious out going link you are penalized. I don’t know how this is possible. Google’s penguin algorithm behaves partial on some sites. This shows algorithm rarely catches paid links only manual reviews catch paid links. Google should show it is ready to punish all sites selling links not just sites they don’t like.