A student from Nanjing University in Jiangsu province tweets to friends. Micro-blogging has becoming a popular way of communication in China, with about 65 million active users across the country. [Han Yuqing/Xinhua]

Fake followers sold for around 0.2 yuan (3 cents) in August 2010, but the price increased to 1 yuan in January.

Almost all online shops claim the "high-quality" micro blog followers they sell are legally registered and have their own individual photos, registration information and fans. Even their micro blog messages are updated from time to time.

A shop owner who only wanted to be identified as Jiou (his registered name on Taobao) provides a service package at his shop: 1,000 followers plus 50 comments plus 500 tweets is priced at 298 yuan ($45.27); 1,500 followers plus 20 comments plus 500 tweets sells for 308 yuan. There's no limit to the number of followers Jiou sells.

According to his site, Jiou earned about 2,000 yuan in December, when he started selling fake followers.

"As micro blogs are becoming more popular, advertisements and false information have shown up. Therefore, the micro blog market needs to be better regulated to prevent deceptive and false information from spreading," said Yin Yungong, director of the institute of journalism and communication of the Chinese Academy of Social Sciences.

Last year, dozens of sensational news items were posted on micro blogs, such as the fake news that novelist Louis Cha died in Hong Kong; while singer Leslie Cheung, who jumped to his death in 2003, was rumored to be alive and well.

"It is typical in a way for some netizens to post striking but false news online and thereby attract people's attention and get more publicity," said Guo Wei, vice-president of Kaixin001.com, a popular online social networking website.

In April 2010, a high school student surnamed Yang, in Wugong, Shaanxi province, tweeted a "forecast" saying that an earthquake would hit the province. The aim was to increase visits and this was "accomplished" when a student surnamed Zhang, at Xianyang Business College, forwarded the tweet several days later. Zhang's tweet scared millions of residents in Shaanxi province and she was later put into administrative detention for spreading damaging rumors.

"The micro blog necessarily gives sparse information and that worsens the situation where micro blog rumors are concerned," Yin said, adding that micro blog users and the public should keep an eye on the truthfulness of the information they receive and transmit.

Most Chinese netizens are rational, but many of them are easily fooled, said Xia Xueluan, a sociologist at Peking University. Therefore, he said, people need to be careful about what they say and how they react while micro-blogging.