We know Google reserves the right to ban all sites on a host if the host seems to have an unusual percentage of spammy sites on it.

Well, Google banned a whole sub-domain yesterday specifically co.cc.

Google’s Matt Cutts actually mentioned it on Google + but now there are lots of threads on the topic. Threads at Google Webmaster Help, DigitalPoint Forums, WebmasterWorld and even Google AdWords Help.

Googler, JohnMu, explained they can do this and have been doing this elsewhere with places like Malware issues. He said:

That being said the Google AdWords Help forum even has an AdWords representative suggesting you do not use co.cc as a domain. The representative explained that although the TLD is not yet banned from AdWords, it is a risky TLD and it is “definitely [in] a bad neighborhood.”

Forum discussion Google Webmaster Help, DigitalPoint Forums, WebmasterWorld and Google AdWords Help.