But changing hearts on twitter ? 4chan ? please be serious ...
I've been on 4chan for a long, long time. And yes, I'm perfectly serious. You can't turn everyone, you have to pick your battles, but ground can be gained and people can be lead to think. Also I think you are generalizing peoples in the chans, I met some nice people there.
But here is my counterpoints :
Every inch of ground you give up is taken by the enemy.
Understanding where the enemy stands in a recquirement for victory
The public debate is an ongoing and sustained effort
Subjecting yourself to different points of views helps you grow as a person
As for turning people with hatred in their heart : I think you underestimate people, by a large margin. Maybe because you haven't been in contact with a lot of extremists, or maybe the extremists you've been in contact have been more extreme than mine. But I've seen people change for the better. Some are just kids, some are misconstruing the nature of their problems, some are just holding the beliefs of their locale community. All of them cannot be turned. Some are actually bags of hate, but they are in the absolute minority.
Allowing you to question your prejudices and your a-priori is one of the functions of free speech, actually.
Edit :
Okay, practical exemple. During the Brexit debate, the question of EU standards was put forth by the brexiteer camp, as an authoritarian top-down, costly and redudant measure by the European Union. That claim was largely uncontested (I think John Oliver made a snarky remark on it at the time, and that was it).
All of it was false, they are actually a democratic process used by the industry to upgrade the quality of their product and to speak the same language across europe, and consumer unions are part of the process of creating standards. Even today, I'm fairly sure the records haven't been set straight in the public opinion.
Now if the proposition is to just systematically abandon the ground and just let everyone live in their own reality, this will happen again and again. We need to confront the bullshit.