They get drugged, their passports and papers are taken away. They are treated psychologically by pimp types. Sometimes their families are threatened if they don't obey. Liam Neeson was in a movie that showed this too.

They get drugged, their passports and papers are taken away. They are treated psychologically by pimp types. Sometimes their families are threatened if they don't obey. Liam Neenson was in a movie that showed this too.