There are organised gangs and there are middlemen but the snatching of children starts with someone local who is desperately poor and needs the money. We found one wily trafficker who realised that there was a better return on kidnapping children than in selling women. He would find out where single parents lived and identified those without many relatives around and targeted their vulnerable babies.
Under the Chinese legal system, migrant workers have very few rights once they move from their home province. They are treated as lower-class citizens and they're found in large ghettos living together. In these places, the only place where children can play is out on the street. Naturally they becomes a target for the criminal fraternity. When they are snatched, the police are not interested in investigating because they're migrants.
In other cases people drive up in a van, throw the child in the back and drive off, but it's generally much more planned than opportunistic. The children tend to be bought by people from richer provinces.
Like any country in the developed world, Chinese couples are postponing marriage and children. And then, the social pressure to have a boy is huge. If you're in your late thirties and you can buy a child for a couple of hundred bucks and guarantee that it will be a boy, why take the risk? Traffickers we spoke to talked about selling a one- or two-year-old boy for around £1,100. Girls might fetch less than half of that.
Girls were being kidnapped particularly for rural families. The family would buy a girl aged seven to eight and them put them to work on the farm until they were of marrying age, to earn back the money that the family had paid out. Then they would marry off the girl to their son, avoiding the need to spend money on a dowry and also keeping both in the family to work.
Jezza Neumann, of True Vision Productions, directed the 2007 documentary 'China's Stolen Children'