The U.S. Trafficking Victims Protection Act, passed in 2000, defines human trafficking as the use of force, fraud or coercion to obtain labor or commercial sex. The term can encompass forced marriage, domestic servitude and the recruitment of child soldiers in war. But it’s hard to pin down the total number of trafficking victims, and the organizations that attempt to do so differ somewhat in their definitions. The International Labor Organization, which uses the term “modern slavery,” has estimated that on any given day, 40.3 million people are exploited, and that traffickers earn an estimated $150 billion in profits every year. The phenomenon, though, is widely misunderstood.