Bumping my question from a couple days ago since I'm curious about some of your thoughts on this matter.
I'll start off by answering my own question and say that I don't think there is a line at all. That is, to say, I believe that it is ethical to do anything on the darkweb. Do I think that *anything* is morally correct just because its the darkweb? No. However, I do think that the darkweb serves as a place that is meant to be uncensored and allowing of things that wouldn't be allowed on the clearnet.
Overall, my personal take revolves around the idea that anything one does on the darkweb is at their own risk. Scamming newcomers? I don't personally support the idea but I don't think it's necessarily "wrong" to do that on the darkweb. The whole notion of scamming newcomers on darkweb forum sites like this one is an interesting topic in itself since I believe it can be used as a defense mechanism versus unwanted visitors like feds. That idea is just one I've personally thought of/theory crafted around though, so I won't go into it unless somebody wants to talk about it.
I went on a bit of a tangent but here's a concluding example of how I feel about ethics on the darkweb:
Trying to look for a place to set up a hit job? Yeah, murder is illegal and I don't support murder but if the person looking to fund or execute the murder understands the risk associated with that and still wants to go through with it, that's on them you know?