It is an open secret that Mark Zuckerberg is pretty keen to get Facebook unblocked in China. But is he taking things just a tiny bit too far?

On Thursday, the Facebook boss posted a picture of himself running through Tiananmen Square and telling his followers how much he enjoyed being back in the Chinese capital.
What he failed to mention was the air was a poisonous shade of gray, officially hazardous to human health. And he wasn’t wearing a mask.

It's great to be back in Beijing! I kicked off my visit with a run through Tiananmen Square, past the Forbidden City and...

Posted by Mark Zuckerberg on Thursday, 17 March 2016

“How far would you go to curry favor with China?” the Beijinger magazine asked in a blog post. “How about running through Tiananmen Square without a mask in this morning’s thick-as-pea-soup AQI 337 air?”

“That’s just what The Zuck-up did this morning,” it continued. “Nice one, Mark. If this doesn’t get Facebook unblocked in China, nothing will.”

Facebook has been blocked in China since 2009, under a system of censorship known as the Great Firewall, although some people can access it using virtual private networks (VPNs). Tech insiders say Facebook is keen to get back into the country of more 1.3 billion people -- even though that would surely mean submitting to the sort of censorship and government scrutiny to which Chinese social media companies are subject.

Zuckerberg has won praise here for his efforts to learn Mandarin, shown most recently last October in a 20-minute speech in the language to university students in Beijing. But he was mocked after President Xi Jinping snubbed his request for the Chinese leader to give his unborn baby daughter an honorary Chinese name.

This is a clip of Mark Zuckerberg's more than 20-minute speech at Tsinghua University in Beijing. According to the Facebook founder and CEO, this was his first time giving a speech in Chinese. (Tsinghua University)

Zuckerberg is due to attend the China Development Forum 2016, a government forum meant to allow it  "to carry out candid exchanges and discussions with global business elites, leaders of international organizations as well as foreign and Chinese renowned scholars."

On social media, Zuckerbeg was gently mocked for the run, and his attempts to access the Chinese market.

"I just want to know how did he post on Facebook in Beijing," asked one Netizen. "Which VPN?" asked another.

On Facebook, Rose Tang, a survivor of the 1989 Tiananmen Square protests now living in the United States, had a warning for the Facebook founder.

"Zuckerberg, did you see the police vans in the square? Do you know anything about Tiananmen massacre? If you pretend you don't, you will be punished -- those who side with dictators and murderers won't have any good ending."

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