Although I don't know much about the technical aspect of it, but

I think GCD don't want to block it with the cell phone roaming (talking about the international websites that are usually blocked in China) when the cell phone service was originated outside of china.

Otherwise who want to travel to China if people can't get access to their bank account, emails, and etc.

 

說白了，就是愚民政策，就是政府不讓自己的人民有了解信息的自由。完全沒有自信心的政府！