As someone who knows exactly what you're referring to, and have seen what the 'dark web' has to offer (chose to avoid some of what it has to offer, because....wtf. Just plain f*cked up, lol)... I would have to agree with the other person who answered this question. Even if exposing this stuff isn't illegal in some fashion, or being on these sites isn't illegal (I'm not sure as to the laws over in Europe, but pretty sure accessing some of that stuff is illegal in the US, even if you don't 'buy' anything or whatever), you could make some very fast, and technologically dangerous enemies. The people that use this part of the web to...do business, to communicate with others, to do...whatever it is they do, do so because they want to remain anonymous. And a lot of the people who use this part of the web to remain anonymous... could probably, very easily, find out who you are, and... find some ways of making you miserable, and wreaking havoc on you/your life. Some of the people on there steal C.C. numbers, and identities, to then be sold later, on the dark web. All sorts of things are done, bought, or sold on there. If you can't find what you're looking for via a Google Search (mainly because what you're searching for is illegal, haha), then you'll probably find it somewhere on the dark web.
So, short answer: I wouldn't think that 'exposing' this stuff, or the people behind the websites, the e-commerce that is there, and whatever else, is a good idea. Not at all. Plus.... Then you're potentially just ruining it for the other people who frequent the dark web, and all that it has to offer. And... that isn't very nice, raining on other people's parades like that. :P