Rampant abduction

Human trafficking has become an increasing social problem in China, and one which seriously violates human rights. As the country has a traditional preference for male heirs, particularly in rural areas, there is a thriving black market for babies who are often abducted or bought.

Some families who do not have a boy are willing to pay tens of thousands yuan for one.

It's a profitable business for criminals. For the children, it can mean a life of begging for money for their owners, stealing and prostitution.

The Chinese government said police investigate nearly 3,000 human tracking cases every year, a figure that includes both women and children. There is no official figure for how many children are missing, although the US State Department believes about 20,000 Chinese children are kidnapped every year.

Peng Gaofeng, 31, is still searching for his four-year-old son who vanished last year from the street in front of his parent's small shop in the southern city of Shenzhen.

Surveillance cameras showed his son being led away by an unidentified man. Since then, life for Peng and his wife has been a nightmarish journey in the hopes of finding their only child.

"Our life has been totally destroyed," Peng said. "I cannot keep my mind on my job any more. We have gone to many cities to find him. My wife is so sad that her weight dropped to only 35 kg from 45 kg."

More than a dozen parents like Peng have similar stories on the Baobeihuijia website. Then, after media attention, the numbers grew to 200.

Unlike the success of Wang, none of their children have been found. Often times traffickers sell or take the children across the country or even abroad.

"During the process of finding children, every family has lots of information and clues which might be useful to other families. But it is never really shared between them because of lack of communication. Thus, a nationwide platform is necessary in the fight against abduction," Zhang Baoyan said. "That is why I built the website."

On it, parents usually post photos of their children, describe their heights and clothes, and express their gratitude to the volunteers.

"After finding missing children, we usually ask them whether it snows in their hometowns, what plants and animals they have seen, what dialects they speak. Then we match these clues with parents who post information on the website."

The hope is that they might have been in an area where other missing children are being kept.