Courts have reported a sharp increase in customer protection cases brought by "professional" consumer rights activists.

In the past five years, almost half of the 661 cases concerning disputes over business contracts and product quality were instituted by familiar faces known for their campaigns against fake and shoddy goods, statistics from Shanghai's Huangpu District People's Court showed.

"Consumers trust them to institute legal proceedings after they find their rights have been infringed," said Jin Minzhen, vice-president of the court. "Sometimes these 'professionals' buy products, which they know perfectly well are defective, and sue the retailers to claim compensation."

Last year more than 40 percent of cases in Chongqing involved a recognized consumer rights campaigner, according to Chongqing No 5 Intermediate People's Court.

In a case in Shanghai in October, a seasoned fighter against fake products and services sued a restaurant on behalf of a newlywed couple. The restaurant falsely advertised itself as a banquet hall to a four-star hotel on its wedding menu, according to court records. The defendant was judged to have committed fraud, and the "professional" campaigner helped the couple obtain their compensation.

But it is claimed some of these "professional" representatives are exploiting their services to make profit. According to the Law on the Protection of the Rights and Interests of Consumers, consumers can receive 10 times the price of a product as compensation if it is found to be counterfeit.

These people don't seek to resolve the dispute first, said Zhang Zengbao, secretary-general of the Consumer Rights Protection Commission of Shanghai's Huangpu district. Instead, they go to businesses and make unreasonable demands.

"In January, a man asked for tens of thousands of yuan in compensation over a packet of food worth just a few yuan after finding faults with the product, and said he wouldn't delete information about the product online until he was paid by the company," said Zhang.

Some of these "professionals" buy goods, thought to be counterfeit, from stores in different parts of the city, and then institute legal proceedings in several district courts at the same time to achieve maximum compensation, he said.

"Consumers can report to us if they find any counterfeit or substandard product. The motivation should not be to make a fortune," said Li Chunyan, a consumer protection official in Huangpu district.

But Xu Dajiang, who is famous in Guangzhou for his fight against fake products, said he is working in support of the official market watchdogs.

"I want to help more consumers to be aware of their rights and protect their interests, and to help suppress the manufacture and selling of fake goods," said Xu, who set up a website on consumer rights protection four years ago.

Some lawyers say the actions of "professionals" should be encouraged as an important non-governmental force to deter counterfeiters.

"If the 'professionals' are forced out, people involved in counterfeiting will be more productive," said Yi Shenghua, a Beijing lawyer from Yingke Law Firm.

"It's reasonable to earn their living in this way, because they have to spend a lot of time and effort on investigation and evidence collection, and they have to be prepared to risk losing lawsuits."

Contact the writer at zhouwenting@chinadaily.com.cn