Some local internet service providers have been running spam adverts on major web portals and chat rooms without paying a cent, according to a nationally televised programme to mark World Consumer Rights Day.
For the 23rd consecutive year, the annual show on China Central Television exposed substandard products in order to promote consumer rights and improved service.
In the programme yesterday, reporters had mysterious ads popping up as they opened the webpages of some popular news portals and chat rooms. None of the website operators knew the source of the ads, which stayed on screens for seconds before disappearing.
In Chongqing, Chengdu, Beijing and Shanghai, a number of local broadband service providers and advertising agents were unearthed earning huge profits by bonding spam with the portals' domain names. In undercover video footage, a manager of Chongqing Information Aviation Service Centre, a broadband service company, said his company ran millions of ads via spam every month, which earned him as much as 8 million yuan (HK$9.88 million) in the second half of last year.
An advertising agent said in the programme agents never signed written contracts with clients and payments would be transferred directly into their personal accounts.
The progamme also exposed that applications on smart phones using the Android system were being used to steal private data without users' knowledge.
Research by a professor at Fudan University found more than half of over 1,000 applications under the Android system secretly sent private data, such as address book contacts and passwords, back to their own servers.
Some application developers said they could even locate the user to the precise place where the app was used.
Some apps were preinstalled in smart phones, others were installed manually by users. In either case, most users are unaware that their privacy is breached.
The state television programme also alleges US technology giant Apple Inc fails to provide the same level of post-sales service in China as they do in other markets.
Apple officials in China and Apple's headquarters in Cupertino, California, were not immediately available for comment.
German carmaker Volkswagen was accused of having faulty gearbox transmission. On its microblog, Volkswagen said: "We take this report very seriously and we will quickly make contact with our consumers to resolve the issue."
The show also exposed an advertising agency in Henan that hired actors to play patients and exaggerated the effectiveness of an adhesive medicine patch, which was made mainly of chili oil but which they claimed could cure diabetes.
An undercover crew also visited Shenzhen Shuibei Jewellery City, the country's biggest gold wholesale market.
A shop owner showed how he could mix nearly 1 gram of iridium, costing 50 yuan to 90 yuan a gram, with 47 grams of pure gold, in less than four minutes. The owner said he had supplied the inferior product to many gold retailers across the mainland.