China's censors have started blocking access to software collaboration site GitHub, and Internet observers are speculating the government's efforts to regulate the nation's online train ticketing system are to blame.
GitHub has confirmed that its site was at least being partially blocked in China, and is investigating the matter, spokeswoman Liz Clinkenbeard said via email on Tuesday.
The blocking may have started as early as last Thursday, leaving the site partially inaccessible, according to GreatFire.org, a group that monitors China's Internet censorship. But by Monday, the site had been completely blocked, the group added.
GitHub is best known as an online repository for open source projects, letting developers share code. Its site has 3 million users, and China ranks fourth among the top ten countries that visit GitHub. Among the top ten cities, Beijing ranks number six.
The country's government has cut access to other foreign sites including Facebook, Twitter, and YouTube, due to their potential to spread anti-government views. But the blocking of GitHub may have more to do with Internet browser plugins designed to make the buying of train tickets online easier, according to GreatFire.org.
The so-called "ticket snatching" plugins have seen a rise in popularity due to the upcoming Chinese New Year, the country's busiest travel season. Users are clamoring to buy tickets from 12306.cn, the nation's official train ticketing site. But services on the site have been slow, and trying to buy a ticket will often result in a page error.
To make buying more convenient, browser providers have rolled out plugins to constantly refresh the site and show when booking a ticket is available, said GreatFire.org in an email. Some of these plugins appear to use files hosted by GitHub.
The plugins, however, have further increased traffic to the 12306.cn site. In response, China's Ministry of Industry and Information Technology reportedly demanded browser providers to stop offering the plugins, according to local press. This likely resulted in the blocking of GitHub.
A ministry spokesman declined to comment on whether it had ordered the shutdown of the plugins, but said the ministry would address the matter in a press conference on Wednesday. The ministry was also contacted about the blocking of GitHub, but did not immediately respond for comment.
Other U.S. sites that allow users to share information have also been blocked in China. Last July, Chinese censors also targeted LinkedIn's, SlideShare service, with the reasons still unclear.