At an Internet service provider, China Mobile Hong Kong, the disconnect – of a type known as dropping – indicates direct involvement by the telecommunications company. “A drop is a specifically configured element of a DNS firewall environment,” said Mr. April. “This is not something that the owner could have set up, intentionally or accidentally.”
China Mobile Hong Kong, the arm of China Mobile, the Chinese state-owned company, declined to comment. Two others tested by the Times, SmarTone and Hutchison Telecommunications, which are controlled by local conglomerates, did not respond to requests for comment via email.
Users of PCCW, another local operator, told The Times that their access to the site was also blocked. A spokesman declined to comment.
While blocking the site looks like mainland China’s censorship at first glance, the methods differ markedly from China’s sophisticated system.
With China Mobile, SmarTone and Hutchison, the process that links a website’s address to the series of numbers that a computer uses to search for it has been halted. The practice would be similar to listing an incorrect number under someone’s name in a phone book. If you know the correct number for that person, you can still call them.
In mainland China, by contrast, the hardware of the Great Firewall – as the Beijing block and filter system is known – actively cuts off connections. In comparison to the phone book, the call would not be completed even if you had the correct phone number.
The Hong Kong roadblocks are “really easy to get around and clumsy,” said Tsui, the professor. Still, he said, officials may not want to control the Internet as strongly as Beijing, for fear of scaring the global banks and international companies that made the city their Asian headquarters.