The kinds of comment one would see on the site:
* Alt-right, anti-Jewish conspiracies. Lots of "Jews in control" posts.
* Raging climate denialism -- almost 100% of the comments on climate change articles were denialist. All the old regulars would show up, and say how corrupt scientists are; how it's all a big hoax perpetrated by "the elites".
* Total cynicism about politics -- a lot of it directed at Democrats. Hillary was a favorite target. Many of the people who wrote these things are not right or far-left, but are just hipsters who are so cynical that they attack, because, "why not?" Then there are the former 9/11 Truthers, who once believed in something (even though it was wrong), who now are basically just alt-righters.
* Racism and sexism, along with adamant denials that they are racist or sexist -- that it's all just SJWs causing trouble.
* More recently: total cynicism about the Russia collusion investigation. It's just power-hungry Democrats trying to take Trump down.
* Anything "official" is suspect. For example, if some U.N. organization reports findings about chemical weapons being used in Syria by Assad, it was immediately called into question, and treated as false without question. WHy? Because it was "official" -- came from "official sources".
All this bilge was blasted out on a daily basis, for years.
Technology Review also deleted their comments section a year or two ago. A lot of the problem seemed to have to do with climate denialism -- anytime a climate change article was posted, a group of people would show up and attack, basically calling the journalists naive and stupid. Jason Pontin, who at the time was the Editor in Chief, got so upset over one troll, he even decided to track him down, and wrote a piece about him:
I have a troll. Writing as @zdzisiekm, or “Gus,” or under other names, he has commented on stories on TechnologyReview.com 6,386 times and counting as of April 2017. As trolls go, he is unfailingly polite, and he doesn’t violate our site’s terms of service. Instead, he is reflexively, tendentiously wrong about a single topic, again and again. Gus is angry about our reporting on global warming and renewable energy technologies. His objections are notionally scientific, but they have a strongly ideological flavor.
Four years ago, commenting on “Climate Change: The Moral Choices,” @zdzisiekm characteristically wrote, “Having studied the relevant science literature quite extensively and in depth—I read hundreds of papers on the subject—there is no real ‘climate change threat.’ It’s all trumped up—the actual published peer-reviewed science is clear on this … This is because in some countries [economists] are so keen to switch the economy away from fossil fuels, they’ll go with any lie …”
I know who Gus is, because I tracked him down. We ask readers to provide some personal information before they can comment, and he wasn’t hard to find. My troll is a sixtysomething technical advisor to the IT department of a large public university in the Midwest. He has not one but two PhDs—in electrical engineering and physics. He writes good research about computer architecture and bad poetry about cats. (I agreed not to use @zdzisiekm’s real name for this story. “I know you know who I am,” he said, “but I cherish my anonymity, and I don’t want people to throw bricks at my window or dent my car.”)
When I asked Gus why he wastes so much time and spirit commenting on our site, he replied, “It doesn’t take much of my time at all. I’ve got a personal database that I can quickly search for specific articles on various subjects of which I have, by now, tens of thousands.”