It's no surprise when China censors a site with anti-government content, but starting last week the country has potentially cut access to scores of non-political sites with a block on U.S. content delivery network EdgeCast Networks.
The "Great Firewall of China" has begun filtering out more sites and networks connected to EdgeCast customers, preventing the services from appearing in the country, the Verizon-owned company said in a blogpost Monday.
"This week we've seen the filtering escalate with an increasing number of popular web properties impacted," it said. "and even one of our many domains being partially blocked...with no rhyme or reason as to why."
EdgeCast didn't mention which specific services had been affected. But from Beijing, sites from its customers including Mercedes-Benz, Sony and humor website Break.com all appeared to be blocked.
"We can say that only a subset of our customers were impacted," Edgecast said in an email. The company has a "number of methods" to mitigate the problems and has given its customers access to them, Edgecast added without elaborating. It has business with over 6,000 companies.
Censorship monitoring group GreatFire.org said that starting on Nov. 12 China had begun disrupting EdgeCast's service, with a block on edgecastcdn.net.
Other sites that appear to be affected include The Atlantic, developer platform Drupal and art showcasing site deviantART, GreatFire added in a Tuesday blogpost..
China, already infamous for its online censorship, has never said why certain sites are blocked, only suggesting that they broke the law in some way. The country has typically targeted Internet services with the potential to spread politically sensitive posts, and blocked access to Facebook, Twitter and YouTube.
Starting this year, however, China has become more aggressive in cutting access to foreign Internet services. In late May, the country began blocking all Google services. Later, the censors went after messaging apps including Line and photo-sharing app Instagram.
The block on EdgeCast may have been an attempt to cut access to one particular site, but ended up affecting several others.
GreatFire.org, which opposes the country's censorship, has been setting up mirror sites so that Chinese users can circumvent the censors and access banned services such as Google search.
These mirror sites work by hosting them on major cloud platforms from Amazon Web Services and EdgeCast, and using an encrypted domain. To block the mirror sites, China would have to cut access to the entire domain.
"In the case of EdgeCast, the authorities have chosen to block access to their service altogether," GreatFire said in its blogpost.