China, more than any other nation, has taken strenuous measures to control what travels over the Internet within China. The government is trying to stop the spread of opinion and news that the government disagrees with. The main concern is criticism of the government, or the communist party, which controls the government (and a large chunk of the economy.) But there's one type of Internet content the government makes no effort to restrict; spam. Chinanet, the main supplier of Internet access in the country, is one the three main worldwide sources of spam (the others are in former communist countries.) Complaints by foreign Internet providers are generally ignored, and as a result a lot of Chinanet's outgoing material is blocked by overseas Internet access providers. This appears to please the Chinese government, which already has Chinanet blocking Chinese Internet users from reaching many "controversial" sites overseas (usually universities and news organizations.) China will not admit that all of this tolerance for spam is official policy, nor will it recognize that Chinanet is also a major source of other Internet mischief (attacks at foreign web sites and other forms of hacking.) Actually, most of the hackers working via Chinanet are from the West, mainly the United States. But America has the most Internet savvy programmers on the planet, and most of the hackers. The bad guys know that Chinanet has no rules or restrictions, so they go through there to do their dirty work. It is feared that China's military cyberwar units are mixing in with the unsavory Chinanet users in order to learn new tricks, and carry out their own snooping, hacking and practicing for some future cyberwar.