One of them was released by the police after being detained for a day in Zhengzhou in Henan Province. Their act has set off a furious debate over the microblog, the state-run Global Times reported.
The report of acts of vandalism against Mao, who has been revered as Revolutionary God for three decades, came as disgraced pro-Maoist party leader, Bo Xilai has been expelled from all posts by the party and awaited trial for various charges of sex, sleaze and covering up the role of his wife Gu Kailai in the murder of a British national last year.
Bo who was expected to run for a top post of the November 8 Party Congress to select new leaders to succeed President Hu Jintao and others is currently awaiting trial.
Any acts of discretion of Mao's pictures in the past would have been considered as blasphemy but not any longer as his ideology was superseded by reforms agenda of his successor Deng Xiaoping after the death of the leader in 1976.
Reports say that the new document approved by the outgoing leadership has no references to Mao's 'Thought' which was once the Bible of the Party cadre.
Mao's large size photo still hung at the historic Tiananmen square but his legacy was very much on the wane, specially among the youth.
But still tearing down of Mao's portrait has "drawn so much fire both online and offline from Mao's supporters that they have received many hate phone calls threatening their safety over the past week," a friend of Cao Xiaodong, who was one of the four men who tore Mao's posters, said.
Xiaodong, 22, a college graduate and a volunteer at HIV aid stations in Henan, was detained for over 24 hours by the Zhengzhou police for questioning before he was released.
The other three participants were not detained or questioned.
Chen Xiaowei, a lawyer from Beijing Yingke Law Firm, told the daily that descendents of Mao can press charges against Cao and the other three for personal attacks, but there is currently no law stipulating that ripping up a portrait, no matter who the subject, is against the law.
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