What does Google in case of duplicate content?
Google answers on his blog. There are two possible cases, a page is duplicated on the same site, in this case we must simply tell Google which page to index, just put the URL in the sitemap. The other will be ignored. The other case is when a site gets your content for display on its site or through proxies. Google takes care to find out which site is the original and which is a copy, that it is not too difficult because he knows the sites. In all cases your site will not be penalized by a duplicated page. Note that when a site is accessible by two domain names, Google can not know which is the original! In this case you’ll necessarily be penalized.
