protest - Closing Pandora's box

As Simon World describes the condrum the Chinese authorities are in as the anti-Japanese sentiments that sometimes even turns against them. For the time being, economic stability is more important and the censors have order the traditional media to stop reporting about anti-Japanese incidents. Simon quotes from the unlinkable South China Morning Post.

Communist Party censors have acted over the rising tide of anti-Japanese sentiment nationwide, ordering all media to drop coverage of public protests against the Japanese government and companies. "No media coverage on anti-Japanese protests [should be allowed]. Journalists should not participate in or conduct interviews to do with anti-Japanese activities," the circular said.
It reminded the media to be vigilant about those trying to take advantage of the anti-Japanese sentiment to put pressure on the government over domestic issues which have triggered sharp debate in the media and internet chat rooms. "[The media] should be highly alert to collusion [among groups which promote] liberalisation, Falun Gong, anti-Japanese [sentiment] and religions," the circular said, using Communist Party references to westernisation and the spiritual group branded an "evil cult" and banned six years ago on the mainland.
"[The media] must attach great attention to the issues and maintain a high degree of political alertness," it added.

In a booming economy any anti-foreigner riots in China would destabilize that economy and I'm pretty sure large scale riots will be suppressed. That might be different, one day, when then economy might not grow and keep the Chinese citizens busy. Then the roaring patriottism could be a convenient way to gather support for the government, but at this stage that is not the case.