I think it's worth saying that abusive can come from any "scene." I think the convention rave thing I mentioned was one of my first real life experiences witnessing it.
I don't know if they are still a thing, but in the mid-2000s it would be common for Anime/Video Game conventions to host all age "raves." I remember walking in and the crowd being people mostly around my age. There were, of course, a few weird dudes in there 30s who really had no business being there. One of the dudes I saw was actually a co-worker of mine at the time. I don't know how old he was exactly, but he had two young daughters (one was 5ish, the other was younger). If I had to guess soemwhere in his 30s? Anyways, that was when I told my friend (who was also uncomfortable) that we should just go. A few months later he got fired for hitting on my female co-workers, who were also in the 16-19 year old range. After getting fired from the movie theatre where I worked, I saw him cashiering at a local Toys 'R Us.
Obviously, this kinda shit you can see in normal clubs as well. Back in that day, I think conventions were more likely to look the other way when someone was acting predatory. I get the impression that shit doesn't fly these days.
I think as far as online relationships goes, this stuff is probably more common on social media platforms like LiveJournal or Tumblr. The communities are bigger and people are more vulnerable, so to speak. I know for example roleplaying communities were big on LJ, and was one of the things that factored in this story. There's this idea that roleplaying as a "character" removes you from your real life identity. I think this line of thinking is still kind of looked over on the internet, though I could be wrong. Now that I am older, that is something I raise my eyebrow at more. I don't think it's appropriate to exchange explicit material with someone underage just because you're "in character."
I think that's why I see this whole story as something completely fascinating but also terrifying. It's like the darkest turn of obsessive fandom, and it's super clear that people who get in that deep have some issues (mental or otherwise) that turn them down that path. In a way I think it's almost indecent to find it so interesting, but it's almost like looking through a lens and seeing what your life could have been like if your obsessions went too far when you were in a vulnerable mental state
It's really sad because I think a lot of people turn to fandom to fulfill some sort of enjoyment they don't really get from their every day lives. As an adult I know how to keep a healthier balance between real life/the internet than I did when I was younger. The sad thing is, I think our generation were the test subjects when it comes to this stuff. That's how you get stories like the FF7 House. Or people like OP who maybe a little too invested and expect too much of uninvolved parties.
That being said, there was a group in university I was somewhat involved in that in retrospect strike me as quite cultish... and that has nothing to do with fandom/the internet. But that's another story, lol.
but then thought 
maybe he's in character and tried to be like 
until he almost fell asleep on the table 
