A Collection of Web Pages About SEO Penalties
SEO Guide: Violations & Search Engine Spam Penalties
Responding to a drumbeat of complaints about poor search results, Google rolled out its “Panda” update in February 2011. Panda targets what is described as “thin” or “shallow” content or content that is lacking in substance.
This domain-level penalty targets sites with a predominant amount of so-so content and essentially treats it similarly to the way it treats overt spam techniques…More at http://searchengineland.com
What Are Google Penalties and What Do They Mean? | WebFX
Depending on how severe the infringement is, they may even be removed from the game, or suspended from playing for a period of time.