Beijing - The Chinese government has declared victory in cleaning up what it considers rumours, negativity and unruliness from online discourse, while critics say the moves have suppressed criticism of the government and ruling Communist Party. Beijing launched the campaign this summer, arresting dozens of people for spreading rumours, creating new penalties for people who post libellous information and calling in the country's top bloggers for talks urging them to guard the national interest and uphold social order. At the same time, government agencies at all levels have boosted their online presence to control the message in cyberspace. "If we should describe the online environment in the past as good mingling with the bad, the sky of the cyberspace has cleared up now because we have cracked down on online rumours," Ren Xianliang, vice minister of the state internet information office, said during a rare meeting this week with foreign journalists. 'Positive energy' A study by an internet opinion monitoring service under the party-owned People's Daily newspaper showed the number of posts by a sample of 100 opinion leaders declined by nearly 25% and were overtaken by posts from government microblog accounts. "The positive force on the internet has preliminarily taken back the microphone, and the positive energy has overwhelmed the negative energy to uphold the online justice," said Zhu Huaxin, the monitoring service's general secretary, according to a transcript posted by state media. Observers say the crackdown has noticeably curtailed speech by suppressing voices and triggering self-censorship, with more liberal online voices being more ginger in their criticism and posting significantly less. Even Zhu suggested the campaign might have gone too far. In one example, Web users refrained from reposting information and commenting on the government response to a severe flood in the eastern city of Yuyao in early October. A year ago, they were garrulous in questioning Beijing's drainage system when a rainstorm ravaged the city. "It is a reminder that we must strike a balance between crushing online rumours and ensuring information flow," Zhu said. Some critics say the moves may backfire by eliminating an effective conduit for the public to let off steam. "If there's no channel for the public to express themselves, they may take to the street," said historian and political analyst Zhang Lifan, whose online accounts were recently removed without warning - possibly because he had shared historic facts that the party did not find flattering. "The governments also can take pulse of the public opinion, but if no one speaks up, they will be in darkness," Zhang said. "It is so odd they are covering up their eyes and blocking their ears." The rise of the internet in China has always been followed by Beijing's efforts to rein it in, and the latest challenge has been the explosive growth in social media, particularly microblogging, which has allowed users to share firsthand accounts and opinions with great speed. Advocates of free speech have applauded the technology as a strong boost to their cause.