Regarding the recent events, there have been a lot of genuine comments from all sides, and although we may not agree with many of them, they are still someone's legitimate opinions. But there has also been an increase in people who are not saying what they really think. Instead, they are writing deliberately to provoke an emotional response. Most of them are probably doing it for fun, but there is also the chance that some might try to get something out of it.

It is fascinating to me that the internet has had at least 25 years of experience with trolls and everyone still does the one thing they should not do: feeding the trolls. Actually, people seem to be barely familiar with the concept as a whole. The meaning of the word has been diluted a lot due to improper usage. When rotavirus was banned, in the discussion that followed, very few people seemed to realize that he did what he did for exactly this purpose.

Let me first reiterate what a troll is. A troll is someone whose comments are designed to provoke an angry reaction out of you. Usually, this involves saying stupid things. Someone being hired to push a certain viewpoint does not necessarily mean they are troll; "troll" does not mean "stupid person" and it certainly doesn't mean "person I don't agree with". It means "person who writes outrageous things to provoke an angry response".

How to deal with trolls

Dealing with trolls is in theory easy, but it requires everyone to understand something. Even a small number of people who feed the trolls is enough to keep them well-fed.

There is only one thing you need to remember. Do not feed the trolls. That means: do not start arguing with them. Why?

1. It is exactly what they want. The troll is now having the time of their life seeing that you took the bait, took their comment seriously and is probably now giggling while they are writing another outrageous comment to provoke you further.
2. You are rewarding their bad behavior by giving them what they want. They now see that you are easily provoked, that this community is easily provoked, and will probably do it again sometime.
3. When you are angry, you can't think properly. If the troll succeeded in making you angry, you might be compelled to write a response. But thinking clearly will not be as easy if you are consumed with anger. The arguments you will make will not be very good, and might in fact be straight-up bad — factually incorrect or even turn out to support the other side. This is also why it is possible to use trolling for a malicious purpose, not just to have some sick fun. You can use trolling to sow discord and confusion, to trick people into making bad arguments and using them against them, making them look like the stupid side for a bystander.
4. As a consequence of the second part of (3), it is possible that you are literally harming the position of your side by feeding the more malicious trolls.

So what to do then? Do you worry that by not replying to the troll you are implicitly agreeing with their statement? No! Codeforces allows us to deal with them very easily. Simply downvote them until their comments and blogs disappear from the public view. Most of them will get bored; only a small number of trolls (shoutouts to Bloodless_Castrator) keep posting garbage even if no one reacts to it.

Recognizing trolls

Recognizing trolls is somewhat more difficult, but it is something that comes with experience. To start, you simply need to realize that not everyone writes only things that they believe, and to start looking at others' comments through that angle. Then you will slowly gain more experience in recognizing them, and noticing their tricks.

When someone is accused of being trolls, a common response is "Oh? So you think people who are that stupid don't exist? Let me tell you...". Well, no, of course such people exist; almost everyone exists. It's much more about how they say these things. Genuine people will try to maximize the chance their views are understood, or maximize the comedic value, or simply vent their emotions. Trolls will maximize the chance their comment provokes a reaction.

It is a matter of experience, and you'd be right if you said that you can never truly know what goes on in someone's head, but the way people phrase things, the way they talk, all this can make someone seem much more like a troll. It is actually quite easy to spot the difference between a troll and a genuine person with the same views, at least with high probability.

An example

In a blog like this, it is important to show concrete examples, otherwise people will understand the content differently. Let me show something from a recent blog. Look at this comment and its subtree. Elegy_No_Programmer is an obvious troll here, I'd say I'm around 98% sure. A correct way to handle the situation would be to downvote and ignore them. Instead, we see a response that would be beyond the troll's wettest dream. About 10-20 people started arguing with them, which is a big number for Codeforces.

You can see that exactly what I said would happen if you fed the trolls, happened here. Arguing with them allowed them to make more comments to provoke people (1, 2, 3, 4 and especially 5). The fifth comment would have looked very unnatural as a direct response to the blog, but it was much easier for the troll to make it look like they believe (5) as a response to a latter comment. By engaging with the troll, you made it possible for them to say "why did India let themselves colonized in the first place".

You can also see how getting angry made others write comments that might not have the best logic like this one, because it makes a very bold and I think false claim; at least in the rest of Europe history books aren't full of how great their country is. This allows the troll to make even more outrageous comments to provoke others, or if they want, to "prove" that their opponents are stupid.

Update

(About 16 hours later.) I'm so fucking disappointed in this community. I explained how trolls work and why it is bad to feed them. I even showed an example so that no one would be confused as to which people exactly I have in mind. And guess what people did in the meantime?

They went and fed the troll.

Dozens of new people in the thread feeding the trolls. They did the one thing they were supposed not to do, they did the one thing they were told not to do. I don't know if it is a matter of reading comprehension, or no one wants to listen to some stupid unrated alt, or what. But goddamn. I hoped to convince at least some people.