China Blocks Content Delivery Network Edgecast, Cutting Access To ‘Thousands’ Of Websites

China’s internet censors have been busy of late, after it emerged that the country’s Great Firewall began restricting access to thousands of websites this past week — including, The Atlantic and Firefox browser extensions — as a result of the apparent blocking of a major content delivery platform.

GreatFire, a non-profit organization that monitors internet censorship in China, reported that “thousands” of websites and apps that work with Edgecast, a service which Verizon bought for $350 million last year, are unavailable in the country.

Edgecast has acknowledged the blockage of a number of its sites in a blog post which explains that there’s precious little that it knows or can do about the situation at this point.

Two key excerpts include:

This week we’ve seen the filtering escalate with an increasing number of popular web properties impacted and even one of our many domains being partially blocked… with no rhyme or reason as to why.

At Verizon EdgeCast we have put policies in place to help our customers mitigate the effects of this most recent filtering but expect this to be an ongoing issue for our customers seeking to reach Chinese users (users in China).

It’s never clear why China’s state censors block specific sites. But in this case, Great Fire makes a compelling argument that Chinese authorities blocked Edgecast as part of a crackdown on a ‘bullet proof’ platform that Great Fire created to allow censored websites to be accessible from Mainland China.

Dubbed ‘Collateral Freedom‘, the Great Fire initiative uses cloud-based services to host websites. Since these sites are registered and exist via a cloud service provider — such as Edgecast or Amazon Web Services, to name just two — the only way for China’s government to block them and ensure that they are inaccessible is to take down the entire network. That would restrict access to numerous other sites and services hosted on the cloud service.

The Collateral Freedom platform had recently been used by independent Chinese news site Boxun, via Edgecast, which Great Fire told Quartz could have triggered the action. If true, then it suggests that China may be willing to cut off vast amounts of content just to keep a handful of ‘threatening’ sites off the menu for domestic internet users.

China’s internet exists in its own space in many ways — Google services have been severely restricted since this summer — but the danger of this approach to cloud services is that it could decouple the country’s population from large chunks of the global internet entirely if other providers are treated the same way as Edgecast.

Great Fire uses a matrix of sites for collateral freedom to mitigate against news like this, so that could mean that we see more mass blocking of international sites as Chinese censors try to figure out how to deal with it.