Specific laws are needed to combat the theft of personal data, according to experts, after seven men were charged in Changsha, Hunan province, with selling more than 100 million bits of personal information online over the past five years.

Information included names and addresses of cell phone users, car owners, company bosses and bank customers, Legal Daily reported on Thursday.

The data were sold on the Internet and used to spam cell phones and illegal GPS devices, authorities said.

Prosecutors said Zeng Zhizhong and Yi Zhijiang spent 4,000 yuan ($640) buying the databases of cell phone users, for instance, in Jiangxi and Hunan provinces over the Internet.

Experts said the illegal use of personal data has worsened in recent years, partly because of improvements in the technology used to find it.

In a survey by the Ministry of Industry and Information Technology released in April, 60 percent of respondents said their private information had been stolen, and the same number had received junk messages.

To see just how easy it is to find personal information over the Internet, a China Daily reporter searched "car owners' data" on the Baidu search engine and was offered numerous links providing data.

An operator on one website, chezhuziliao.com, said it charges 1 yuan for 10 car owners' information. To prove the authenticity, the operator e-mailed a list of 100 car owners in Beijing, dating from May to June 2011.

The list included car owners' names and addresses, license plate details, cell phone numbers, car brands and models, and even the serial numbers on car frames.

China Daily called one of the owners on the list, who said he received many unexpected calls from insurance salesmen — but he was surprised and concerned to hear his own information was actually being sold.

"A thief calling you and standing in front of your home may break in at any time. That's more dangerous than receiving harassing promotion calls," he said.

Many laws and regulations cover the issue of private information — including about 40 enacted by the national legislature, 30 by the State Council and 200 by ministries, and banking and insurance regulatory commissions.

However, Yang Lixin, a law professor at Renmin University of China, said the legal framework lacks a clear definition for private-information protection.

"Courts pay less attention to the offense because there is no detailed explanation or definition on the subject," said Yang.

Ruan Qilin, a professor at China University of Political Science and Law, said many suspects arrested in a police crackdown of the crime last year were released, after the evidence collected failed to be strong enough to prosecute, because of the weak definitions.

Ruan added that China needs specific laws on private-information protection that would properly regulate who can handle and manage personal information.

Citizen awareness in protecting privacy should also be enhanced through further public education, Ruan said.

Contact the writer at [email protected]