China's Ministry of Industry and Information Technology and the State Council Information Office, which regulate China's Internet industry, didn't respond to requests for comment.

WSJ: China's Internet 'Wall' Hits Business

As of the end of 2007, more than 26.5 million rural households were using household biodigesters, saving the equivalent of 44 million tons of CO2 emissions, according to China's State Council Information Office.

CNN: 'Green' revolution under way in rural China