Police officers make a list of bank cards seized in a telecommunication fraud case in Xuchang, Henan province, in January. NIU YUAN/CHINA DAILY

Three of those arrested by the police are middle-level executives of the company and the others are delivery personnel. They form a complete industrial chain with the middlemen, and buyers, who are mostly salespeople of health foods companies and real estate agents.

The private information they trade is not restricted to telephone numbers and home addresses, but also their clients' e-commerce records, which is of commercial value to the buyers.

The judicial authorities issued an interpretation on how laws apply to crimes infringing on citizens' private information in May, specifying the penalties that can be meted out to such "insiders" who make use of their jobs to steal people's private information and seek illegal gains by selling it.

If the amount of information or illicit gains made surpasses a certain level, the culprits should be handled according to the Criminal Law, rather than the public security regulations.

But the difficulty in obtaining evidence against them and the ease with which they can make money mean there are always those who have access to people's private information and take the risk of stealing it.

Apart from legal penalties and cracking down on such crimes, measures are needed to preempt the rampant theft and sale of people's private information.

The authorities should not only target the sellers, but also the other parties in the chain.

The judicial authorities need to call to account the employers of those caught selling private information. The e-commerce, delivery, telecommunication, banking, transport and healthcare institutions as well as the other agencies in relevant industries also need to strengthen their internal management and supervision to prevent employees from taking advantage of their posts to fatten their own pockets. And last but not the least, the buyers of the information must be held accountable too.