Skip to main content

China blocks ‘thousands’ of sites by censoring entire content delivery network

China has ramped up its online censorship programme by blocking one of the Internet’s largest content delivery networks (CDNs), cutting off the country from large swathes of the web.

The nation is well-known for blocking high-profile sites such as Facebook, Gmail and YouTube, but this is the first time such a widespread measure has been implemented.

Read more: China blocks Instagram as it looks to censor Hong Kong protests

The Greatfire blog is reporting that EdgeCast, one of the largest CDNs in the world and provider of cloud services to thousands of websites, has been blocked.

“The Chinese censorship authorities have DNS poisoned *, which means all subdomains of are blocked in China,” it confirmed.

The censorship has been implemented in order to block’s mirrors of sites already censored in China. This means that the Chinese government has prioritised the blocking of particular sites to such an extent that it is willing to cut China off from the global Internet. Users are already reporting that, Mozilla add-ons and Gravatar, a service used by sites to display images, have all been affected.

Greatfire added that the authorities are likely to have been informed regarding the impact of the EdgeCast censorship.

“If the authorities did not anticipate what damage the blocking of EdgeCast would inflict, they have likely been alerted by the many companies that use EdgeCast in China,” it said.

The decision to block EdgeCast could be the source of some embarrassment for the Chinese government, particularly with the country set to host the World Internet Conference later this week.

Read more: Twitter opening Hong Kong office despite China ban

It is not yet clear if the CDN will be unblocked during the event, but even if that proves to be the case, the censorship is likely to resume once the conference is concluded.