According to Rebecca McKinnon, an expert on Chinese internet censorship, China is already getting to grips with Google Buzz, filtering out parts of the new social networking service as they pass through its Great Firewall.

But this is one service that China’s overworked internet censors may actually have a reason to welcome.

As Evgeny Morozov pointed out in a blog run by Foreign Policy magazine, there’s a great irony in Google’s failure to give its users adequate controls to protect the privacy of their Gmail contact list when joining Buzz. A month ago, the company was complaining loudly about attempts from inside China to break into the Gmail accounts of well-known dissidents and others around the world. Now, some of those very same people could well be inadvertently disclosing the names of their closest contacts.