I had spoken to several women who entered 'the trade'. they got money for flight,plastic surgery,room, and board. because of that, a lot of their money is kept until they 'finish their contract' and go back to their home country. human slavery does happen, but its not the default case. and while its true people are 'exploited' due to not knowing all their options, etc, but thats no different than what happens in other work environments. think: why do employers often forbid talking about pay?
the human trafficking narrative emerges from the idea that when it comes to prostitution, many were starting to realize how senseless outlawing it really was, and that many of the fear claims associated with it were inaccurate. so they changed the topic from prostitution to human trafficking.
as research has been finding out, the negative feelings associated with 'whores' & 'sluts' is most often propagated by wealthy women trying to protect their status.