A Beijing resident surnamed Wang never thought a text message on his mobile phone would cost him more than 150,000 yuan (US$18,500).

Last week, Wang was stunned by a message that claimed he had bought items with his credit card that totalled more than 18,000 yuan (US$2,200). He said he had not used the card.

Anxious, he dialled the number that the message left to contact the bank staff, and he was asked on the telephone to leave his card number and password for further identification. Later Wang found the spending limit on his account had been reached. When he redialled the contact number, there was no response.

Wang's case turned out to be high-tech fraud, and he is only one of many who were cheated through a short message service (SMS) via mobile phone.

The Beijing branch of China Unionpay, a national bankcard information exchange network, reported it had received thousands of inquiries from worried credit card holders about their accounts during the just-ended National Day "golden week."

China has more than 370 million mobile phone users, and hundreds of millions of short, or text, messages are sent every day, making it a profitable value-added service.

But mobile phone subscribers are frequently inundated with unsolicited SMS transmissions, from lewdness and sexual services real or virtual to cheap airline ticket ads and other marketing ploys.

There is no official data on the extent of the problem, but many mobile phone users in China have complained of receiving suggestive short-message spam, pornography and other illegal content.

"Legally, the sending of short messages containing text or pictures with pornographic content or false content, violates regulations, pollutes society and spreads a very bad influence," an expert from the Ministry of Information Industry said. The telecom industry regulator needs to expand its oversight of telecom operators and service providers, said the expert from the Telecom Institute under the ministry who gave only his surname, Lu.

The ministry has already launched a campaign to check telecom operators and service providers this month.

(China Daily October 12, 2005)