Bloggers not allowed challenge the communist system in China

Users of blogs and internet chatrooms will be required to register their names with operators and promise in writing to avoid challenging the communist political system in China.

The announcement follows what technology companies say are official efforts in recent weeks to block virtual private networks that are used to circumvent China’s extensive internet filters.

China has the world’s biggest population of internet users with 649 million people online but increasing censorship has limited the popularity of social media.