Most Beijing newspaper booths have stopped selling prepaid mobile phone SIM cards as they wait for instructions from the three main phone companies on the implementation of new regulations requiring purchasers to register their identities. Twelve China Unicom automatic machines at Terminal 3 of Beijing Capital International Airport have also stopped selling cards. They can now only be bought at one service centre at the terminal, with foreigners allowed to buy one after showing their passports. A customer who bought a mobile phone top-up card at a newspaper booth near the Dawanglu subway station in the capital's Chaoyang district said he would not give his details. 'I don't feel safe about it. The information can be easily sold,' he said. Mobile users who already have anonymous prepaid SIM cards will have to provide their real names and ID card numbers within three years. Zhao Yumei , a spokeswoman for Beijing Newspaper and Periodicals Retailing, which manages the capital's 2,500 newspaper kiosks, said 4,000 workers would be trained to register the identities of customers buying prepaid SIM cards, following the introduction of the nationwide requirement on Wednesday. 'We have asked our 50 wholesale centres across town to carry out training sessions based on their own schedules. Some have already begun basic training,' she said. More systematic training would be organised after the retailer signed contracts with the three phone companies. Four out of five newspaper kiosks near Dawanglu have stopped selling all SIM cards. One kiosk is selling only China Unicom cards. 'I said no to more than 10 customers who wanted to buy a prepaid SIM card on Wednesday, including two foreign students,' one vendor said. 'We are waiting to be notified when the service will be resumed.' Another vendor had been given forms that customers needed to fill out before buying a China Unicom SIM card. It requires them to provide their name, contact number, address and a photocopy of their identity card. A hotline was set up yesterday for reporting newspaper vendors who violate the regulation. They face fines of 5,000 yuan. Similar policies for mobile phone numbers have been put in place in other countries, including Japan, South Korea, Singapore, Thailand and South Africa, to tackle the threat of terrorism and drug crime. But mainland activists are concerned the personal information could be used to monitor and track down protesters. China has tightened its control over the internet by blocking Facebook and Twitter and implemented real-name registration for online games last month. Gu Wei , an employee at a consulting company, bought two prepaid SIM cards for his company at a China Mobile service centre yesterday, registering them under his own name. 'Everything is moving towards using real names,' he said. 'It is supposedly effective in regulating frauds and scams.'