""In some instances, you can only get high marks on performance if you perform" without using condoms or other protection, Graham said."
Back then, I didn't think about the effect recommendation systems would have outside filtering bad clients. This negative effect on positive reviews is totally believable after all the stories I've seen about people extorting eBay or Amazon store owners for good reviews. This needs further research to figure out how to reduce its effect. It's essentially a form of subversion in practice where prostitutes get positive reviews the more dangerous (i.e. STD's) they are for their more honest clients. On top of pregnancy risks.
I have to further speculate that the same type of 'impact' we see from legalizing 'recreational use' would also be mirrored with this topic; possibly to an even more positive degree.
I did a lot of research on that in college for some legalizing prostitution essays. The research I found, both scholarly and anecdotal, totally supported this. The worst thing I found is that there were many incidences of rape or abuse by clients, pimps, or even cops that were made easier to get away with via the stigma of prostitution. Just bringing up the details of the crime was enough to get themselves arrested. In some cases, judges tossed it out since they equated prostitution with asking for it.
So, taking action like this isn't just taking a stand against the act of prostitution: it's also supporting worse crimes to happen to prostitutes and others around them. Not even necessarily people participating. It can be just a caring person that runs afoul of the pimps that want the status quo to remain for specific women.