Xinhua and other Chinese media recently reported, with great calm, “Putin criticized Lenin. He said, ‘Lenin’s ideas eventually led to the collapse of the Soviet Union.'” 
The report of Putin’s statement may turn out to be an event of some consequence in China’s ideological history. Lenin was the founder of Communism in Russia and the Chinese Communist Party (CCP) inherited that legacy. To the CCP conservatives, criticizing Lenin is the same as denouncing Mao Zedong, the first generation leader of the CCP. It undermines the very pillar of the CCP’s legitimacy. Thus it is definitely a taboo in China.