“Trafficking” is not a thing. It is not an event. You cannot point a finger at it or take photograph of it. “Trafficking” is a convenient, simple and useful label attached not to a single phenomenon but to a complex series of states and events that individually may or may not be harmful or wrong.
ILO (International Labour Office). Trafficking in Human Beings: New Approaches to combating the Problem. Special Action Programme to combat Forced Labour. May 2003: 2+.