June 5, 2009 -- Deng Huidong's heart breaks every time she sees her neighbors' children playing in the street. Their smiles and youthful laughter only help to remind her of her own son, who was abducted more than a year ago.

Ye Ruicong was nine months old when he was snatched from his sister's arms on Nov 12, 2007, after kidnappers pulled up next to them in a white van in Dongguan, Guangdong province.

A mother cries as she is reunited with her deaf son in Shiyan, Hubei province. He was abducted from a special education school along with four classmates in 2007 and rescued by police in Changsha, Hunan province, following a 15-day search.

"I saw the van taking my son away," sobbed Deng. "I chased it for as long as I could, but it disappeared. There was nothing I could do."

One year on, and she has scoured the province in search of Ye, begging for help from every local public security bureau and posting information on street corners and in newspapers. So far, her desperate efforts have been in vain.

Deng is just one of the parents whose lives have been devastated by child trafficking, which has become an increasing problem in China since the 1980s.

With most families in the country still wanting male heirs, particularly in rural areas, a thriving black market for babies has developed, with children either abducted or bought from impoverished parents.

Families who do not have a boy are sometimes persuaded to buy one from organized gangs for tens of thousands of yuan. It is a lucrative business for some and, if not sold on, abducted children may also face a life of begging, crime and prostitution.

Police in China investigate around 3,000 human trafficking cases every year, with victims mainly women and children, said the Ministry of Public Security.

There is no official figure for the number of children still missing, although a report by the US State Department suggested as many as 20,000 children are kidnapped in China each year.

Public security bureaus are often singled out for criticism over child trafficking, being blamed for a reluctance to investigate, as well as poor efficiency and procedures.

Dongguan, a major Chinese city of industry, has had 121 cases of child abduction since 2000, said the city's bureau.

Only half have been solved.

"It is hard to find evidence and investigate as there is a big floating population (of migrant workers) in Dongguan," said Li Zhuohua, a criminal police team leader for the bureau. "Besides, after the traffickers transfer and sell the children to buyers, it becomes too difficult to trace them."

The Chinese people are refusing to stand idly by and have joined forces with public security officials to battle the criminals.

After being kidnapped and then moved between Hong Kong, Shenzhen, Guangzhou and Shanghai for three months, a 16-year-old girl surnamed Wang was finally returned to her parents in north China on May 22.

She was snatched in the city of Datong, Shanxi province, in February and was only found after the intervention of a private website.

"Her parents asked our website for help, so we sent information, including a mobile phone number the human trafficker had left, to the Ministry of Public Security," explained Zhang Baoyan, 47, the founder of the Baobeihuijia Volunteers Association. "The police arrested the suspects, freed the girl and sent her home."

The association, based in Tonghua, Jilin province, has brought together more than 10,000 volunteers, mostly the parents of missing children, to search, collect and check information. Since it was founded in January last year, Baobeihuijia, which translates as "baby back home", has helped recover 36 children.

"During the process of looking for children, every family has lots of information and clues that might be useful to other families. But it is never really shared between them because of a lack of communication," said Zhang. "So this nationwide platform is necessary in the fight against abduction. That is why I set up the website."

Parents use the site to post photos of their children, along with details about their height and distinguishing features, for free, while volunteers based across China upload information on suspected child traffickers and children they think may have been abducted.

"After a missing child is found by police, they are asked whether it snows in their hometown, what plants and animals they have seen, what dialects they speak. The officers then pass these clues on to us so we can match it against the information posted by parents on our website," said Zhang.

The success of the venture has come with great risk, as Zhang and fellow volunteers are often threatened with violence.

One of her colleagues, who uses the name Zai Zai, has helped rescue 37 children since 2007. A young man who appears easygoing and trustworthy, he meets trafficking gangs and poses as a potential child buyer as part of sting operations.

An outraged parent in Chengdu, Sichuan province, breaks through onlookers and launches an attack on a child trafficker in policy custody on Feb 23. The district court held a public trial for three traffickers who abducted eight children aged four to six and sold them to families in Fujian province.

"I've developed a way of detecting traffickers. When I have enough evidence, I report them to local police ," Zai Zai told China Daily.

Zhang added: "Some volunteers are exposed to criminals while trying to get clues. We must try our best to protect them from danger."

Government red tape, however, has hampered some of the group's ambitious activities, as has a lack of funds.

"We wanted to put the information of children in orphanages online, so parents can get access. But the local civil affairs bureau always refuses as they think it violates the children's privacy," said Zhang, who runs the website from her home in Tonghua.

"So far, we have received about 10,000 yuan ($1,500) in donations, which has been spent on helping the released children go to school or see doctors. But now I want to build a foundation to be able to reward those who report useful clues."

The success of the website has received much attention from the government. In April, Zhang was among nine Baobeihuijia volunteers invited to Beijing by the Ministry of Public Security to discuss anti-abduction measures with top officials.

"The officials accepted lots of our suggestions, such as how to build a DNA database to help identify abducted children and how to start investigations quickly after receiving reports from parents. We are really proud," she said.

The central government launched a crackdown on human trafficking in April and published a list of the 10 most-wanted offenders. So far, four have been arrested.

Police at all levels were also ordered to conduct more interviews with the public to gather more clues on existing cases.

"Lots of useful information lies in our hands thanks to volunteers spread across the country," said Zhang. "After the discussion in Beijing, we were encouraged to provide clues about possible human traffickers, potential buyers and children suspected of having been abducted. The ministry has also set up a DNA database and aims to have all 236 laboratories in China linked as soon as possible. The bank will store samples from parents to match against a child suspected of being abducted or living on the streets.

Zhang's next priority is using her website to help those youngsters found roaming or begging in the streets.

"Most street children are abducted and forced to beg by their owners. They are often abused and lead miserable lives," she said. "Some traffickers even freeze a child's arms in a refrigerator and break them off. The more miserable the children look, the more their owners earn.

"People should not give money to these young beggars, instead they should call the local police. Although, many cities do not have the polices to help street children."

During the search to find her son, Deng Huidong has met many parents in Guangdong in her position. She has now collected information on more than 200 missing children. "We have united to find our lost children. I still believe my son could return to me someday," she said.

Peng Gaofeng, 31, is searching for his four-year-old son, who vanished in March from the street in front of his family's small shop in Shenzhen.

Surveillance cameras showed the boy being led away by an unidentified man. Since that day, life for Peng and his wife has been a nightmare.

Both are volunteers for Baobeihuijia and, last month, Peng's wife gave birth to their second son.

"When he grows up, he will seek his elder brother with us and become a volunteer," said Peng. "Perhaps, I'll never see my eldest son again, but I just pray the same thing doesn't happen to another family."