The Chinese government has imposed new disclosure rules for microblog users in an attempt to clamp down on the spread of “unfounded” rumors and other irresponsible behavior.

Under the new measures, users will have to register their real names and mobile phone numbers in order to post messages online. Those who do not wish to provide such information will be prohibited from posting messages and will have reduced ability to read others' notes.

The rules take effect immediately in Beijing, and they are expected to become the norm in other cities, including Shanghai and Guangzhou.

The regulations are likely to raise objections on the grounds of limiting free speech and curbing the dissemination of news and information.

Chinese microblog sites like Weibo (which boasts almost 300 million users -- equivalent to the entire population of the United States) have become a powerful source of information for many people in a country where official news is heavily censored by the state.

Weibo, which is similar to Twitter, has become a sensitive matter for government officials as users often use the platform to criticize government policy.

Wang, a young government employee, told Reuters that if he cannot post messages anonymously, he will no longer do so.

Definitely, I will not use Weibo if they need real names, he said. I don't want to be supervised because of my words.

On Thursday, the stunning news of Communist leader Bo Xilai’s sudden forced departure was heavily covered and commented upon on the microblogs.

Yesterday, when I did a search for the term 'Bo Xilai,' it returned 1.2 million results, Rachel Lu, editor of Tea Leaf Nation, which reports on China's social media, told the BBC.

Last night, when I did the same search, there were 180,000 results. So a lot of censoring already happened in that time.

Another Chinese citizen, a young bank employee, addressed her concerns to Reuters. I'm sure I will not use it any longer, she said. Weibo, for me, is just a tool to blow off my anger and pressure. I won't be able to shout [about] abuse in future.

However, such blogs have also spread false reports.

A few months ago, an incorrect rumor that the new leader of North Korea, Kim Il-Sung, was murdered in Beijing, gained traction and spread like wildfire across Chinese blogs.

It appears most Web users are abiding by the new rules. According to reports, 60 percent of Weibo users are expected to comply by the disclosure requirements.

A Beijing resident named Qiu Yun told Computer World that while she is against the new requirements, she will continue blogging.

“After the real-name registration goes into effect, I will be cautious about sensitive topics and radical opinions, she said. Most people just write about their lives. They don't question, or at least don't criticize politics.

Interestingly, the new rule comes into effect one day after outgoing Premier Wen Jiabao stated that China needs to accelerate reforms and make meaningful progress towards democracy.

Meanwhile, social media sites like Facebook and Twitter remain unavailable in China

He Weifang, a law professor at Peking University and a regular micro-blogger himself, explained that the popularity of sites like Weibo arose due to the sub-standard news reporting published by state-controlled media.

China's official media has done a very poor job of reporting criticisms of the government and exposing society's weaknesses, so a country like ours needs to rely on the informal media, he told Reuters.

Once the people can express their opinions online, they don't have to take to the streets.