China's largest microblogging service Sina Weibo has introduced new rules aimed at preventing the spread of information deemed inappropriate by Internet regulators, under which an account would be suspended or even deleted if the user posts "sensitive content."

According to the Sina Weibo Community Convention and a series of supplementary regulations that went into effect on Monday, microblog users are to be given 80 initial "credit points," which will be deducted for each violation as determined by the service provider. Their accounts will be terminated when the balance reaches zero.

Users who post "sensitive information" will be silenced for 48 hours or even kicked out of the popular cyber community, if the "offense" is deemed serious.

Sina defines "sensitive information" in its newly issued rules as "information that harms national and social security," which includes contents   banned by relevant laws and administrative regulations.

Sensitive information is content with "sensitive words" that has nothing to do with the authenticity of the information, and the definition of "sensitive words" is based on our country's relevant laws, a client service employee of Sina told the Global Times Tuesday.

The convention, which will impact approximately 300 million users, is also formulated according to "relevant laws" and does not require public opinion consultation, she added.

"Freedom of speech can only be limited by laws. For example, it is inappropriate to post content advocating subversion of the state," Wang Zhenyu, a Beijing-based lawyer and a deputy director of the Public Decision-Making Research Center with the China University of Political Science and Law, told the Global Times.

Wang added that no Chinese laws have clearly defined the term "sensitive words" or designated a pool for such words.

A total of 5,484 voluntary Weibo community committee members have been recruited by Sina, who will judge the content of the posts and decide what to do with the users if they fail to comply with the rules.

"Only the courts, not microblogging service providers, have the right to judge the authenticity of the content and decide what online behavior infringes on others' rights or are in violation of Chinese laws," Wang added, noting that the committee lacks legitimacy.

The new convention has triggered concern among Weibo users. Hu Yadong, manager of the Sina Weibo operation, said that "absolute freedom is actually not freedom" and restricting someone's right of speech guarantees the right for others.

He said the regulation was released to benefit users, and will not affect their loyalty to the platform, the China National Radio reported.

Supervision over the booming microblog phenomenon has gradually tightened in recent months. In late March, Sina and Tencent microblog services were required by Internet authorities to ban commenting services for three days to clean up rumors.

In an effort to better monitor what is being posted online, Beijing has introduced rules requiring all of the country's microblog users to register using their real identities.

Liu Xiaoying, a professor of international journalism at the Communication University of China, told the Global Times earlier that strict supervision of the increasingly popular microblog is necessary when it comes to fighting against false information, but the regulators should also ensure people's right to know while pursuing social stability.

The public relations department  of Sina could not be reached for comment Tuesday.