Globalisation has brought the world's goods to the west. But how can rich consumers be sure they are buying food and clothing manufactured without harming workers - especially children? Humphrey Hawksley reports. [Transcript:] We told several big UK retailers what we found in the factories. None would be interviewed. Some referred us to...Ethical Trading Initiative...[refers to Nestlé, Mandhana Industries, Tommy Hilfiger (part of Phillips-Van Heusen), Gap, Walmart, Marks & Spencers, Zara (part of Inditex)]