Selling second-hand clothes is a global industry estimated to be worth at least a billion dollars a year. Most of the clothing is donated from people living in the US, UK, South Korea, Germany and the UAE. They are sorted by quality and condition, with the best garments ending up in Latin America and parts of Asia. Everything else goes to countries in Africa. In Nigeria the trade is illegal, but the industry is still thriving. In the second of a three-part series on the second-hand clothing industry, Al Jazeera's Mohammed Adow reports from Lagos.