There are a number of ways China cuts off access to websites it deems inappropriate for its populace. It can co-opt telecoms companies as part of its Great Firewall to simply blacklist sites one by one. But it can also shut off reams of websites in one fell swoop by blocking companies that run content delivery networks (CDNs).
CDNs host copies of websites on servers in different countries so people in those areas can access content at greater speed. But by filtering or blocking the IP addresses of CDN servers, instead of individual sites themselves, China can force huge swathes of sites to experience slowdowns and outages at once.
Videos by VICE
That’s precisely what has happened this week, according to anti-censorship body GreatFire and the CDN provider affected, Verizon-owned EdgeCast. “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,” EdgeCast said in a blog post.
The activists behind GreatFire have one idea as to why, and it’s nothing to do with Verizon or any of the popular sites that EdgeCast delivers to China. GreatFire has been creating a slew of mirror sites that have been blocked on the mainland, which GreatFire then promotes through Github and other sites that are often deemed to important to block. These cloned websites are hosted by EdgeCast, a CDN that GreatFire had assumed was also too important to censor.
It seems like an odd time for Beijing to be launching such a blunt offensive on web freedom: Starting Wednesday, the country will host the World Internet Conference this week in eastern Zhejiang province, which aims to promote a web that provides “global shared resources for human solidarity and economic progress.”
GreatFire.org noted in its own blog post that thousands of websites have been cut off, as all subdomains of edgecastcdn.net have been blocked since at least November 13. This has taken out a range of sites that appear to have no obvious connection, from Mozilla Firefox’s add-ons page to The Atlantic and Sony Mobile’s English and Chinese pages.
The original EdgeCast announcement, screenshotted by GreatFire.org
Hitting CDNs in the interest of targeting only certain websites is a dangerous game, as it leads to collateral damage that could infuriate masses of Chinese web users.
“Given the amount of the internet that’s distributed by large content delivery networks such as Fast.ly, LeaseWeb, Amazon, Akamai, etc., CDNs can provide an appealing target for censors,” Morgan Marquis-Boire, a former Google security expert who’s now in charge of protecting the website The Intercept, told me over email. “Having said that, blocking them wholesale is not without collateral damage, as I’m sure users in China are finding out.”
The latest batch of websites cloned by GreatFire on EdgeCast servers included the Chinese-language news site Boxun, which a representative for GreatFire noted “has a history of breaking pretty big news stories in China, almost all of which have been censored by the authorities.” Using the pseudonym Charlie Smith, he told Quartz that he’d seen “nothing on this scale ever before.”
China’s censors play a continual cat-and-mouse game with sites deemed dangerous to national stability. One closed-door session at this week’s three-day internet conference will focus on “Constructing a Peaceful, Safe, Open and Cooperative Cyberspace.”
While a number of executives from China’s internet giants like Alibaba, Tencent, and Baidu are expected to show up, along with executives from Qualcomm, Microsoft and Samsung, Xinhua reports, the speakers include only two non-Chinese executives, from Qualcomm and LinkedIn. A current and former representative from the internet oversight group ICANN will also be in attendance. Curiously, one China correspondent noted, the internet at the conference would be “uncensored.” (Update: Bloomberg Businessweek has verified that the internet would be unblocked for three days at the conference.)
“China appears eager to promote its own domestic Internet rules as a model for global regulation. This should send a chill down the spine of anyone that values online freedom,” William Nee, China researcher at Amnesty International, said in a statement on Monday about the conference. “China’s Internet model is one of extreme control and suppression.”
EdgeCast noted the frustration of customers, which it said it shared, along with “the whole content delivery and hosting industry,” according to its blog post. “Rest assured that we stay committed to work with our global ISP partners and do our best to mitigate the effects of these filtering policies to ensure a clear path to your users and customers in China.”
It said customers could log onto their EdgeCast account and tweak settings to mitigate filtering, but could not guarantee this would maintain their visibility in China, nor would it tell Motherboard what technical measures they could take.
The targeting of a Verizon entity in particular comes amidst recent concerns about and attacks on US technology companies in China. Last month, Chinese hackers allegedly intercepted iCloud passwords, and have been accused of hitting Hong Kong protest sites hosted by another US CDN provider CloudFlare with distributed denial of service (DDoS) attacks, with some success.
Matthew Prince, CEO of CloudFlare, said his company hasn’t seen an uptick in its IPs being blocked, but it does happen and “is something we carefully track.” CloudFlare is used to such behavior, as it works with a number of high profile targets. In recent months, it’s been helping Hong Kong protesters’ sites and online services of the Hong Kong government.
