Don't forget that the words 'pimped' and 'trafficked' tend to be used very loosely: by ourselves, by abolishionists, by legislators.
Morally there is a world of difference between a wonan working voluntarily and one who is not: a difference not always recognised sadly.
Under English law, 'trafficked' can include someone who was trapped into prostitution but it can also mean something as innocuous as an agency arranging transport or a working flat for a WG on tour when the WG made her own decision to escort freely and willingly (in other words the majority of escorts who firmly don't want 'rescued' from their chosen job.)
Probably some EEs are indeed trafficked or pimped in the bad sense, something that every right-minded punter is opposed to. Studies suggest that if the law were reformed it would be easier for such cases to be exposed, without normal prossies and punters being put off becoming 'involved'.
In cases where (particularly, I think, many Polish WGs who come over here), they simply hire a 'Sergei' ( often a woman) to write their profile and arrange a flat. (A bit like Soho walk-ups.) Sometimes 'Sergei' does a good job and sometimes he/she is a cunt. So the objection is not whether there is a Sergei but whether a) s/he does a good job in representing the WG's voluntary interests or is career criminal cunt, and b) whether s/he does a good job in representing the WG honestly on her profile to punters or just ticks everything. The second one may be intentional or non-intentional, depending on his/her level of English.
Not sticking up for the intermediaries where there are any, but remember the word tends to tar everyone with the same brush, from the horribly coerced foreigner to the genuine UK student who pays some guy to arrange working flats to save her the embarrassment and hassle, and so she can escort to pay for her education, booze, shoes and nail varnish.