Trolls, according to the latest research, aren’t just bad people on the Internet. They’re bad people in real life. They’re narcissistic. They’re manipulative. They periodically enjoy causing others pain if only to demonstrate their own importance to themselves.
Stipulate that this research is more true than false, for a moment.
Next: consider your views on (some version of) the Judeo-Christian understanding of “Original Sin.” If, like me, you believe that all humans are prone to proud, blindly self-regarding behavior, then this research should give you pause. If all of us are, more often than not, prone to narcissism and self-deceiving false righteousness in real life, then we are all trolls from time to time.
And comments sections encourage this. They shield us from many of the real life consequences of being ugly and behaving badly. Which, to my mind, makes them especially bad for discussion, and—more importantly—bad for us.