This issue comes up now-and-again here, so maybe it's time to put it in perspective.
You seem to be saying:
1: These girls are paid less than the going rate.
2: They probably can't advocate their interests well, because of the language berrier.
3: They may be afraid of their other alternatives.
4: They're going through this purely for the pleaure of American men, so maybe it's even worse.
You'd get no argument from me on any of those points. You'd also get a long list of legal, mostly male-staffed jobs that fail the same criteria.
Case in point: Most of the local hospitals use a medical records system called Epic. The company is based is Wisconsin and run by a woman. She hires Chinese developers who are here on work visas. If ther're fired, they go back to China:
http://www.bing.com/images/search?q=chinese+executions&go=&qs=bs&form=QBIR They aren't highly-skilled developers who can code in zSeries assembly and name their own salaries; they're grunts who kinda know PHP and CSS and would be making pretty basic lower-middle-class money even if they'd been born here. They're making less than that and working really bad hours.
If you're saying that the hobby is special because it's a luxury, or because of the health risks for the ladies, I'd disagree there too:
Lots of people work in shitty, dangerous, corecive jobs so that your wife can throw away a working toaster just because it's last year's style. In human terms:
1: Somebody had to mine the materials.
2: Somebody had to truck those materials through a no-man's-land to get them to the edges of civilization.
3: Somebody had to refine them.
4: Somebody had to ship them across an ocean.
(Oil companies used to have legendarily bad shipbuilding standards because the ships were crewed by foreigners and paid for after a few runs anyway. Who cares if a dozen Central Americans grunts drown after that? They only got in trouble when they killed a British crew.)
5: Somebody had to work in the factory that made the toaster (maybe soldering by hand with lead- and cadmium-bearing solder, certainly working with tools that could cut a finger off if they were careless).
6: Somebody had to crew the ship that brought it over here (see above).
7: Somebody had to crew naval ships that police those lanes - and they are, *by law*, not there of their own free will.
8: Somebody had to work in the shipyards and drydocks to keep those ships running.
9: Somebody had to work on the dock, walking around under multi-ton cargo containers dangling from cranes and hoping to God that the wind wouldn't shift.
10: Somebody had to drive the truck that got it to the shipping warehouse.
11: Somebody had to haul big heavy skids around in the warehouse.
12: Somebody had to stand over hot tar in 120 degree heat to repave the road that those trucks wore ruts into.
13: Somebody had to walk around a foundary with a carafe of white-hot molten steel to cast parts for the heavy road-building machines needed to do that.
14: Somebody had to stock the shelves.
15: Somebody had to ride a garbage truck, weather be damned, to take away the old (still working) toaster.
16: And on, and on, and on...
...all so that cossetted housewives can have designers toasters, and 12-year-old Paris Hilton wannabes can have cute little tablets with no useful apps on them.
You could say that the people who work in those jobs are all bone-heads who couldn't get better work, but would you make that kind of argument about girls being trafficked? (It's also not true: I have at least one friend who escaped a war-zone to come here. He had to work his way up the hard way, while learning the language and the culture, trying to live a life and support his family. He wouldn't have gotten out of his home country alive if he hadn't been at least a little clever.)
Some people have said here that even trafficked girls get a better deal than they would have overseas. Whether that's in-bounds or accurate, family newspapers make that argument about low-wage, mostly-male jobs pretty regularly.
I also get that the ladies don't like cut-rate competition. I doubt that any of us do. Do you pay more for US made clothes? Would you pay more so that my job isn't offshored?
Speaking of clothes, there are two local suppliers of police tactical gear and uniforms. (They also sell other stuff.) I told a clerk at one of them that I wanted something US made; almost none of it is. Most of the labels list an East Asian origin. There's a good chance that the cops who bust sex-trafficking rings are wearing clothes made with coerced labor (and maybe child labor) while they're doing it.
I'm not really this self-righteous. You're only asking me to pass up something that I don't really need anyway (economical hot sex). I'm game. But what will you do for someone like my refugee friend? Also, I live pretty cheaply compared to most women of similar means. Not crudely, mind you. I like *nice* things. But it's rare that I buy something unless it's (a) functionally much better than what I have, or (b) to replace what I've worn out. Most of the rest goes into savings. If we're talking about net harm to human life, I think that my record stacks up pretty well. If you're willing to stop working people to death all over the globe so that little girls everywhere can have "cute" accessories, and you're willing to ask whether something is really useful before taxing the poor to pay for it, then I'll gladly play ball with you. (I mean that.)