Beijing -- Miss Ke used to log on to her desktop MSN messenger all day, because her company used MSN as a cheap communication tool for colleagues and clients.

She was so used to this convenient online chat device she sometimes indulged in short, intimate conversations with her handsome boyfriend, until one day that she realized that their conversations were public knowledge.

"I was shocked to discover that everybody knew what we were saying to each other, because our MSN Messengers were monitored and the technical engineers couldn't keep their mouths shut," said Ke, who works for a foreign trade company in east China's Zhejiang Province.

"I feel hurt when my colleagues make fun of me by quoting our private words," Ke said.

Ke's case is increasingly common. Software that can monitor online chat rooms such as MSN Messenger, Yahoo! Messenger and ICQ is widely available in China, and many companies justify their surveillance practices as a means of preventing the leakage of business secrets.

According to the Shanghai Morning Post, an employee with a bank in Shanghai, identified as Lisa, quit her 30,000 yuan (US$3750) per month job last October for the same reason as Miss Ke.

A recent survey by a web company called China Job Online showed that 89.2 percent of respondents used chat tools, such as MSN and ICQ, in their offices and about 20 percent said their companies had installed cameras or software to monitor chat content.

Half of the respondents considered the surveillance a violation of employees' privacy and said they would appeal to the courts if it happened to them, the survey said.

Miss Ke was advised by her lawyer Su Hongtu, an attorney with Huatai Law Firm in Hangzhou city, to take her employer to court.

"Miss Ke could accuse the company if she has authentic evidence to prove the technicians purposely revealed and spread her private conversations," Su said.

When Ke asked the head of the surveillance department for an apology, he refused to give one. The head said his department monitored employees' MSN to prevent them from revealing the company's confidential documents to outsiders.

Su Hongtu said the company may be justified in monitoring employees' MSN, which is used mainly for business, during office hours. However, the technicians should keep private conversations secret, even if their access to them is legitimate.

A technician with Microsoft Corporation, owner of MSN Messenger, said users could prevent private talk being monitored by installing encryption software.