Feng Zhenghu, Shanghai's most famous dissident, announced last week that he wanted to launch a manifesto on human rights.
His "Shanghai Expo of Unjust Court Cases" was intended to be a critique of the city's legal system, an alternative view to the officially manicured image of China's business capital.
But within a day, the police were at his door. They confiscated his computers and interrogated him for four hours.
The 55-year-old former economist is a well-known irritant of the authorities in China. Mr Feng spent three years in prison between 2001 and 2004 for his calls for democracy. He had written about forced evictions and bad behaviour by local authorities.
But he secured his place as one of China's most famous dissidents when he spent three months stuck at Tokyo's international airport unable to travel to home because the government was angry about his rights activism. He was refused re-entry eight times and lived off the goodwill of fellow travellers in the no-man's land of the immigration section.
He finally got home in February and was placed under close surveillance at his home in Shanghai but continued trying to expose injustices surrounding the Expo.
He wrote a document calling for freedom of speech and for an end to the tight control of the internet.
In an interview with the rights group Human Rights in China, Mr Feng told how he has been placed under heavy "protection".
"Beginning in March, they placed a group of five people outside the door of my home, to take turns watching after me 24/7. They have orders from their superiors to follow me whenever I go out. They are watching me so tightly, ostensibly to 'protect my safety,' " he said.
However, according to the Hong Kong-based group Chinese Human Rights Defenders, the police swooped on his home last week after his manifesto announcement.
They said that if he spoke out during the Expo, which is intended to showcase China's rise, they would make him disappear like another of China's most prominent activists Gao Zhisheng, who was missing for many months after police took him away.
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