China's hugely popular Sina Weibo microblogging platform has stepped up controls on what its users can post online, warning that anyone posting too much "inappropriate" content could be banned from the Twitter-like service.
From Monday, Sina Weibo users who post five items of "sensitive" news could be barred from posting for 48 hours, while anyone judged to have posted "harmful information" could have their accounts revoked "in serious cases," the company has told its users.
"We began to implement the investigative arrangements on May 28," said an employee who answered the phone at the Sina Weibo customer helpline. "Sensitive words are judged according to Sina's rules and regulations and Sina's specific [requirements]," he said.
"There will be investigations, but the results will vary from person to person," he added.
The move, which will target information deemed harmful to national security, junk advertising, and pornographic material, drew condemnation from veteran Chinese bloggers.
Blogger Wen Yunchao, known online by his nickname Beifeng, said Sina was responding to increased pressure on service providers from China's ruling Communist Party.
"I think Sina is doing this for the benefit of the government, because the government is currently awarding points for service providers' performance," Wen said.
"They want Internet portals to carry out their own checks, and if they don't score enough points their licenses could be revoked."
"All Sina is doing here is transferring some of that pressure onto its users, forcing them to censor themselves," he said.
Process 'more obvious'
Citizen journalist and veteran blogger Zhou Shuguang, known online by his nickname Zola, said China had imposed controls on microblogging services all along, but that now this process was becoming more obvious.
He called on service providers to hold a debate with netizens to avoid losing public trust.
"This is Internet surveillance in a black box," Zhou said. "This sort of surveillance lacks transparency."
"The only surveillance I would accept would be transparent surveillance, in which every rule and regulation had been subjected to [public] debate."
Wen said he had opened a Sina Weibo account earlier this week, only to have it immediately deleted before he had a chance to tweet anything.
"Sina deleted an account I had only just opened and hadn't even used yet," said Wen. "Once you are on the blacklist or the list of dangerous persons, then they will delete you anyway."
Chinese computer experts say the government has continually sought ways to limit freedom of expression on the Internet since people started using it, and that controls on the nation's 250 million microbloggers are only the latest step in that process.
Struggle for balance
According to Jia Xijin of the school of public management at Beijing's Qinghua University, many Internet service providers are struggling to find a balance between their users' demand for nongovernment news sources and the tight information controls required by the ruling Communist Party.
"A lot of online services, especially microblogs, don't entirely abide by freedom of expression," Jia said.
"But this rule of Sina's will affect the way people view freedom of expression, in the event that netizens get overexcited, or start talking about various matters of public interest."
He said the new rules could well mean that microbloggers begin censoring their own online comments.
"In the long run, this won't have a beneficial effect on the liberation of new truthful reporting about society," Jia said.
Beijing-based microbloggers have been prevented since March from registering an account on one of the country's hugely popular Twitter-like services in anything but their real name, verified by their national ID card.
The move has been slammed by netizens and rights groups alike as a huge blow to freedom of expression in China, where 513 million netizens rely on forums, social media, and bulletin boards to find news and views that have been censored out of the tightly controlled state media.
However, authorities have detained a number of netizens and online editors over retweeted material that was deemed controversial under new guidelines aimed at preventing the spread of online "rumors."
Earlier this year, authorities in Guangdong province detained Web forum editor Shang Laicheng after he reposted an Internet forum message alleging that local prosecution officials had used the services of prostitutes.
In March, the overseas China Human Rights Defenders (CHRD) group called government controls on microblogs "the most alarming development" on the Chinese Internet of the past year.
"The thriving domestic microblogsphere has proved highly effective in exposing government misconduct during the past few years, but it is now threatened with curtailment," the group said in its annual report.
Reported by Lin Jing for RFA's Cantonese service, and by He Ping for the Mandarin service. Translated and written in English by Luisetta Mudie.