Regardless of what people think about the industry it's a difficult and exploitative industry with a very short lived career path for most who choose it and a lifelong stigma that goes with participating... which often gets girls doing this by first asking them to do a naked photo-shoot which is then used as a opportunity to upsell the girls porn shoot... In the case of GDP it was with an all paid ticket to a different town -- and that might sound exciting at first if you don't know what you are getting in to.
There are other far worse forums out there that run for-profit and seem to show no sign of stopping, unfortunately. Some of them have an actual real-world death count (and that's the point).
Don't really know how you solve it. Censorship isn't the answer (even if it were, how do you get it universally applied in countries that might host these services), and there aren't shared morals here to apply either. The legal system? Maybe, but it moves so slowly...
It would cost a million dollars to find one poster, but it’s worth a billion dollars to strike fear into their hearts that they could be identified and named and shamed in lawsuits and judgements in their home towns.
(Although in a very real way, every lawsuit is a government action.)