Sex trafficking has evolved in the 21st century to focus heavily on social media and financial mobile applications. And despite efforts to stop it, it's increasing globally.

In 2010, Lawrence Ray, a 50-year-old ex-con, formed a sex cult at his daughter's dorm room at Sarah Lawrence College in New York and humiliated, tortured and trafficked members for his pleasure and monetary gain.

The British socialite and Jeffrey Epstein conspirator was sentenced to 20 years in prison for her role in recruiting, grooming and abusing teenage girls over a decade. What made these girls trust her?

Abdon Pallasch, former legal affairs reporter, spoke with A&E True Crime about his years reporting on R. Kelly and why it took nearly three decades for the singer to be prosecuted for his crimes against underage girls.

We speak with author Sarah Berman on her book, 'Don't Call It a Cult: The Shocking Story of Keith Raniere and the Woman of NXIVM.'

Sex trafficking is big business. Globally, it generates tens of billions of dollars in profit every year. Here in the United States, it ensnares hundreds of thousands of victims. And while the stereotypical image of a trafficking victim is a foreign national, many of the exploited are underage American girls.