Child labor has been a longstanding scourge in the $100-billion cocoa industry for more than two decades. Despite efforts by U.S. Congressmen, African governments, the world's biggest chocolate companies and various non-profit groups, it has been a tough nut to crack. In this episode, we look at program that actually seems to be having an effect. It uses a network of smartphones to identify child laborers on thousands of remote farms in Ghana and the Ivory Coast. It then tries to persuade farmers to stop using their children on farms and to send them to school instead. You will hear from cocoa farmers in Ghana, from Nestle, maker of KitKat, and a Swiss non-profit group called the International Cocoa Initiative, or ICI, which co-founded the program. (Photo: AP)