Yuan Xiangzhen and her son became couriers four years ago to pay a 100,000 yuan ($16,000) debt to a usury company. In 2013, with the help of the media, the company exempted interest on the loan.

Yuan, who is 66-year-old, always carries the mail packages in her left arm as her right leg was broken and she doesn't want to put more pressure on it.[Photo/CFP]