3. Sexual slavery
The International Labour Organization estimates that there are 4.5 million victims of forced sexual exploitation.
Shandra Woworuntu, an activist against human trafficking, was forced into sexual slavery in the US in 2001.
She left Indonesia when she was promised work in the hospitality industry in the US, but the agents who met her at the airport passed her on to armed traffickers, who forced her to carry out sex work.
"They told me I owed them $30,000 and I would pay off the debt $100 at a time by serving men," she said.
She eventually managed to escape, and helped the FBI locate a brothel with other trafficking victims.