SHANGHAI: The phone calls started soon after Chen Xin's wife received her first pregnancy examination.

The callers offered a variety of services for the couple's as yet unborn child. The only trouble was that nobody knew Chen's wife was pregnant except his wife, Chen and the hospital.

"She left my phone number at the hospital," Chen said. "A few days later, the first calls started coming in, offering care and private health coaches for my wife. Then more followed, offering everything from insurance to brushes made from the baby's hair."

Chen's family's case is just one example of how people's private information is increasingly winding up in the hands of people who are using it for commercial purposes.

"This has happened to so many people," said Chen. "People often complain about insurance agents calling to talk about policies that best fit their needs, or decorating companies calling soon after someone buys a new apartment.

"It has to be the hospital that disclosed my information," Chen said. "The hospital was the only place that had my phone number. Nobody else knew about my wife's pregnancy."

According to a report on CCTV, 74 percent of the country's urban residents have been the victims of some sort of privacy disclosure. Of the total, 90 percent of the disclosures involved people's contact information, such as a phone number or an address. Forty-two percent had their information disclosed through the Internet after registering on a website.

Lei Gang, a lawyer, said it is illegal for people to sell personal information for commercial use, though there are no specific regulations on how such information should be managed. The lack of clarity surrounding the issue has opened the door to situations like the one that Chen's family experienced.

The lawyer advised people to be sure to keep their personal information secure, and to install firewalls on their personal computers. And he also urged victims of information disclosure to keep a record of the incident in order to provide evidence when the time comes to make a complaint.

In another case, a man surnamed Ren became the target of frequent harassment by decorating companies soon after he purchased an apartment in Wuchang, Hubei Province. He eventually discovered that the company that managed his apartment building had sold his contact information for 1,000 yuan (about $130), and that many real estate developers and property managers made extra money by selling people's personal information to decorators.

"I had no sense of security. Some even called me three times a day," Ren said.

Other sources of personal information include online groups like alumni clubs and resumes submitted to job-hunting agencies.

"It felt horrible when I typed my name into a website and loads of information about my educational background started popping up," said Rachel Yang, a recent university graduate.

"I thought being part of an online alumni club would be a good way to keep in touch with former classmates, but I never realized that it would reveal so much about my personal life."