Mao Yushi, the 84-year-old economist known for his criticism of China's Great Helmsman Mao Zedong, has once again found himself at the center of a vitriolic debate.

After making comments online indicating that he had received threatening phone calls in the middle of the night, fierce debates erupted between his supporters and opponents.

The harassment faced by the economist was the latest incident in a series of cases that began with political debates online then developed into abusive events in real life. Victims not only included liberals such as Mao Yushi but also Maoist scholars like Sima Nan.

Analysts and observers see these events as signs of an emerging divide in the public's ideological views and are calling for reason and rationality to be exercised when political debates get heated.

Escalating abuse

It started with a speech Mao Yushi delivered on economics and the private sector in Shenyang, Liaoning Province, on March 25. Five minutes after the speech began a man stood up and fiercely shouted protests at him.

"What kind of economist are you?" the man shouted. "Is it really economics you have been talking about?"

After shouting these words, the protester, who was later identified as Wang Xinnian, the deputy secretary general of the Liaoning Society of the History of the Communist Party of China, was quickly taken away from the auditorium by guards.

A few days later, Mao Yushi started to receive abusive phone calls at home in the middle of the night. In one of the messages he showed to the Global Times, an anonymous man called him a "deceitful traitor" and threatened to hurt him if he didn't shut up about the Great Helmsman's "faults."

The threatening calls continued for about a week until Mao called the police. The harassment stopped but the protests didn't.

Mao Yushi had to cancel his speech in Changsha, Hunan Province, due to security concerns on May 4 after opponents held "condemn the traitor Mao Yushi" banners in downtown Changsha protesting his appearance.

In a face-to-face interview with the Global Times on Monday, Mao Yushi expressed his concerns. "I know a lot of people disagree with me, but I've never wanted to silence these voices. I hope people can do the same when I disagree with them."

History of anger

It was not the first time Mao Yushi was caught in the center of controversy.

In April 2011, when Mao first published his article Rethink Mao Zedong as a man, the website Utopia, formed mainly by Mao Zedong's supporters, established a prosecution group aimed at placing the economist in a public trial to punish his "traitorous rhetoric and anti-people speech."

Mao was not the only controversial figure in China that had been harassed or attacked.

Wu Danhong, an assistant professor at the China University of Political Science and Law, who is also known as "Wu Fatian" on Sina Weibo, was allegedly beaten by Zhou Yan, a female reporter from the Sichuan Television Station, in July 2012.

Despite the fact that they had never met in real life, they had already engaged in several vitriolic debates on the Internet, with the most recent being about whether a molybdenum copper project in Shifang, Sichuan Province, was polluting the land.

Sima Nan, an outspoken Maoist scholar who happens to be one of Mao Yushi's biggest critics, had a shoe hurled at him by a young man during his speech at Hainan University in October, 2012.

The young man loudly challenged Sima's opinions and expressed his disapproval of the political ideology of Sima's theories before he expressed his dissatisfaction in a physical way.

Aside from the young man, more than 10 people were prevented from entering his lecture when they were found carrying stones and eggs, presumably to be thrown at him, Sima later posted on his Sina Weibo.

Both Mao and Sima are influential yet controversial figures in China despite their vastly different views.

"Sima stresses the importance of maintaining the current system of socialist core values and emphasizes that a stable political environment is crucial for the revival of China. Mao, on the other hand, believes that China must carry out reforms and should learn from the political models in the West," said Xie Hui, a law professor from the Beijing Institute of Technology.

"Their experiences show that the once uniform ideology in China has become very divided and the ways people today, despite their political opinions, tend to express their disapproval in physical and violent ways," Xie added.

No holds barred

Both Sima and Mao Yushi have been given insulting nicknames by their opponents.

Sima has been dubbed "50 cents," a pejorative slang term that refers to Internet commentators allegedly hired by the government to post comments that favor government policies. They are said to be paid half a yuan ($0.08) for each post.

Mao was called the "American dog," a spiteful term for people who are inclined toward Western values.

"The hate in these names and the attacks that followed show how immature the environment for political discussion is in China," Zhou Ximing, a professor from the Party School of the Central Committee of the Communist Party of China, told the Global Times.

"The spirit of debate does not exist among a majority of Chinese. When it comes to political views, people still see them as either right or wrong. So the next question is, who is right and who is wrong and what to do with the people who are wrong? But political debate is much more complicated than that," said Zhou.

Opinion leaders on the Internet also warned of a loss of belief in today's society and cautioned that such emptiness leads to social unrest and rage as shown in these online-to-offline attacks. Others see it as a painful but inevitable part of the development into a civil society.

"Our country has been under one uniform ideology for a very long time. People are not used to having others challenge their opinion. They often feel offended and link such disagreement with disrespect, which is why many respond angrily and violently," Li Dun, a political science professor from Tsinghua University, told the Global Times.

"What happened to Mao Yushi and Sima is very much a way for people to vent their frustrations. It is brutal and immature in a way but looking at it from a different point of view, it shows that people today are learning how to participate in political discussion," Zhou added.