THE Chinese new year, which this year falls on February 10th, is a time of family reunions. But Xiao Chaohua is preparing to spend his sixth new year without his son, who was abducted in 2007 by suspected child traffickers. China’s one-child policy has fuelled demand for children like his, thousands of whom are snatched and sold every year to desperate, usually boy-less, couples. Spurred by the campaigning of parents like Mr Xiao, the government is starting to acknowledge the practice more openly. But curbing it is proving tough.

Mr Xiao has been trying the hard way to raise awareness of the crime; driving around the country in a minivan covered with posters of missing children. One of them features his son, then five years old, dressed up for a school photograph in a white jacket with red lapels (see picture). Mr Xiao, who lives in a village near Tongzhou, one of Beijing’s satellite towns, says he has spent as much as 400,000 yuan ($64,300) of his own money on the project. He says there are other parents elsewhere in China who tour the country in similarly bedecked vehicles.

The authorities have launched several crackdowns over the past two decades, but the crime has persisted. Since a renewed effort began in 2009, more than 54,000 children have been rescued and 11,000 trafficking gangs “smashed”, Xinhua, the state news-agency, reported in December. Officials claim the problem has become less rampant.

Given the patchiness of official data, this is hard to prove. Individual cases of abduction are rarely reported by the state-controlled media. But Deng Fei, a Beijing-based journalist and prominent campaigner on behalf of victims and their families, believes the number of children being abducted is falling. Mr Xiao estimates that the price of abducted boys has risen in recent years from around 40,000 yuan to about 90,000, perhaps because the supply of abducted children has been affected by the police crackdown.

Social media may also have played a role. In recent years, parents and activists have been using websites and microblogs to share information about cases and draw public attention to child abduction. Their efforts have put pressure on the police, who have responded (unusually, given their suspicion of internet activism) by using the internet themselves to contact the families of victims.

The police official in charge of anti-trafficking, Chen Shiqu, has an account on Sina Weibo, one of China’s most popular microblog services. Its main page shows a cartoon drawing of him, cuddling a rescued baby. “Have mobilised to verify”, he wrote on January 23rd in response to a message from another microblogger about a missing child. His account has 3.4m followers. Mr Deng, the journalist, has 2.8m people who follow his microblog, which he uses to help return rescued children to their parents. An account on Sina Weibo run by Baobei Huijia (Baby Come Home), an activist network based in north-eastern China, has nearly 140,000 followers. Mr Chen, the policeman, is a keen follower of the activists’ work, say the Chinese media. Zhang Zhiwei, a lawyer who helps Baobei Huijia, says the public security ministry has encouraged police to join internet groups that discuss child abductions and engage with members openly. This is a novelty for the publicity-shy police. China Youth Daily, a Beijing newspaper, reported that Mr Chen began his online outreach under the pseudonym “Volunteer 007”, but his mastery of the subject had soon led to his identity being revealed.

Mr Xiao, the parent, believes the authorities could be doing a lot more. Buyers of abducted children still often get away without punishment—they usually live in villages and sometimes enjoy protection from local officials. He says orphanages sometimes fail to take DNA from children they receive. This can be used to look for matches with DNA records held by anti-trafficking police. The absence of such checks allows traffickers to sell children to orphanages, which can then offer them for adoption at high fees.