Friday, May 27, 2016

All of Tumblr blocked in China because of a 29s porn

What happened?

Tumblr is officially blocked in China beginning yesterday, joining the long block list of similar services such as wordpress, blogspot, etc.  Blogger and Google sites has been blocked since 2009 and wordpress joined them in 2011. Almost all foreign web services that involves user generated content have been blocked in China, including Facebook, Twitter, Youtube, Instagram. GFW clearly has noticed political content on Tumblr years ago but somehow decided not to block all of Tumblr till now.  According to Alexa, Tumblr is ranked 153 in China, rather well for a foreign website.

I'm not shocked at all that Tumblr is finally blocked. In fact, the opposite is true, that I'm very shocked that Tumblr is not blocked till now. Many individual blogs on Tumblr has long been blocked for years., tumblr of famous circumvention tool fqrouter has been blocked since 2013;, or Corruption China, has been blocked since 2014.

Reason behind the block

Tumblr is probably blocked because of 陆家嘴不雅视频. It refers to a 29s porn video spreading like crazy on the Chinese social network and was later reported by major media and newspapers. The video was deleted by censorers on Chinese social network. But the original video comes from stalkeryan{.}tumblr{.}com (NSFW) and the tumblr supposedly hosted the full version of this video and many other videos like it. The blogposts on tumblr has been deleted.  But the video is still available if accessed directly.  vt{.}tumblr{.}com/tumblr_o40da56RLU1v5eoup_480{.}mp4 (NSFW)

This is the first time a major website is blocked for non-political reasons.

Technical details

Tumblr is blocked by 
1) connection reset based on blacklist. "" is blacklisted and any URL containing such word will trigger the blocking by GFW. 
2) DNS poisoning based on blacklist "" and exact match of "". Any subdomain of tumblr such as "" will trigger GFW to inject fake DNS response. 

Those are the most severe methods of blocking. GFW could have chose to block the specific subdomain of the offending tumblr like before, but GFW probably think enough is enough and decided to block all of it. 


  1. China has been very demeaning to the “freedom of speech” because it blocks and bans anything that might send the governing authority chills down its spine. When i was in china, i was connected to china vpn for accessing blocked sites.

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