According to Hong Kong news papers published on 17th, the anti-Japan demos that took place in China on 16th had been designed by the Chinese government.
"This [the protests] is definitely no coincidence. It's a typical example of diverting attention," rights activist Pu Fei told Hong Kong's Apple Daily. "It's to shift the public and netizens' focus away from [Noble Peace Prize winner] Liu Xiaobo and [his wife] Liu Xia."
University students, who are under control of the government, had planned the demos for more than a month. Since the students aren't allowed to do any political activities without authorization by Communist Party of China, the demos were virtually government-led.
That means the Chinese government attacked Japanese companies on purpose.
Some Japanese media previously asserted that the anti-Japan demos happened as counter-demonstaration to anti-China demos in which people surrounded the Chinese embassy (almost always favor China).
The truth is that the series of the anti-Japan demos had been planned by the government-led students.
I'm not certain if all the demos were administered by the Chinese governement, but at least the series of demonstrations were initiated by the Chinese government.
How did the Japanese surround the Chinese embassy?
No wonder the Chinese government needs a scapegoat.