Reddit Has Become a Battleground of Alleged Chinese Trolls

I think right now there are three main kinds of internet trolls in things like this. First would be the government sponsored ones who tend to post in unison or have some theme. These seem to mainly be Chinese and Russian. Second are the freelance trolls, people in it to make money by building an audience for advertisements. A lot of these people are in Macedonia where they can make relatively good money spreading false blogs on Facebook or something. Finally are the home grown true believers who are just posting their honest views in an abrasive, hostile, or threatening manner. I think the majority of trolls belong to the last group, but the first two have an outsized impact at creating new stories and coordinating messaging that is amplified by the third.

Trolls are not persons, they are characters.

There were a lot of trolls in the old days of newsgroups, and none of them fit in any of your categories: they were neither in it for the money, and they certainly were not true believers. They were in it for the entertainment. The best way to fight them was to ignore them, hoping that the lack of reaction would bore them.

In 1997, imagine that you are arguing with the user Voldemort on comp.sys.mac, as he is claiming that the Mac is awful, that Mac users are idiots, and that surely Apple will be dead by year 2000. Maybe J.K. Rowling agrees with you that the iMac will save Apple. But that's completely irrelevant because you are not arguing with her: you are arguing with the evil character she created, that wishes death upon the Mac world. What you need for Voldemort to calm down is not to win the argument against him, but to convince the author of altering the behavior of her character. An entirely pointless endeavor...

EDIT: that said, I agree that the internet landscape has massively changed since the nineties.