For example: When someone on HN said over the weekend "I don't see anything inherently wrong with colonialism. Remember that scene from Monty Python -- What have the Romans done for us? A lot of good has come out of colonialism", I was almost certain (almost) it was trolling. Once I saw others agreeing, I reconsidered. What you may consider trolling, may be the other idiot's actual views.
I bring this often on HN, and I will do so again: such trolls (and people who actually believe what they say) are really really threatening to the internet, and everything it has mostly stood up for. When every woman is threatened with rape and murder, and every person of minority is humiliated (often under the pretension of 1) irony, as in reddit, and 2) strictly unemotional data-based Vulcan objectivity (as is often the case here)) , the internet loses its most powerful component: the diverse group of people using it.
I absolutely believe <500 low-paid shills with medium-level English can bring down sites like the likes of reddit. Bringing down does not mean putting them out of business -- that's rather incidental -- it means creating fear and terror amongst a large part of the users to convince them that the majority of the internet is against them -- the internet is not the place for them. It is not just threatening women or minorities, obviously -- it could also be pretending to be an extremist feminist, and suggesting men should be hanged, burned etc, provoking the other group, and causing conflicts.
This is the issue why a lot of platforms have struggled with harassment and bullying issues, and it tickles me when the HN crowd --predominantly libertarian-- drones on about 'free speech at any cost' (suggesting that any removal of extremely offensive content is tantamount to utter censorship), not realizing that an absolute free-for-all arena is most likely to be used by the parties with the most available resource to shape the conversation easily. To put it differently, if Russian trolls can reshape (partly?) the conversation, so can the American government, and so can any agency, with enough resources. To reiterate, it is not necessary to completely change people's point of view -- just scare a targeted population away from a location, and identifying that is NOT as simple as 'calling out the trolls'.
I'll offload something tangential too here. When women say 'there are issues for women in technology', fellow HN users, the least correct response is to offer 'well maybe if they worked harder instead of wasting time complaining, they'd have less issues'. That actually happened in one of the last few discussions about women in tech.