This is a problem so vile and ugly that no one wants to look. THANK YOU, Jenna for looking.
This is also a problem made exponentially worse with lax\non-enforcement of 1st world immigration laws. These girls are most often shipped out of the country from which they are kidnapped, and are “traded” internationally. Not vigorously enforcing border and immigration laws allows their captors to hide them from law enforcement in the host country.