So there's a brilliant flowchart. Drawn by someone who actually knows how to draw flowcharts. I can just leave it here to address the topic of trolls. Sure. He's addressing reading your Amazon reviews, but it's all the same, isn't it? You don't here the good ones. You only obsess over the mean, crappy ones. Thus, the decision tree for how to handle Amazon reviews (sub in trolls).
What? I shouldn't just leave that here and walk away? Dang. Okay. How about the Psychology Today article pointing out what the internet, even in infancy, knew about trolls all along? That they're narcissists, psychopaths, and sadists. Not that I'll claim the internet knew any such thing with the experimental and researched certainly that Psychology Today likely knows it - but who among us had been on the internet for more than an hour before being given the Second Rule of the Internet: Don't Feed the Trolls (the First Rule is: All Caps = Shouting = You're Making Yourself Look Bad). The interwebs, in its amassed unconscious wisdom, knew from the get go that the only way to deal with trolls was to starve them out. That by denying them sustenance, we'd be essentially trolling the trolls.
Trolls are all about themselves. No one else. It's all about them. Always has been. Always will be. Little dried up emotional vampires, they feed upon any and all reaction they can elicit from others. The danger to you is that this is how they multiply. Responding to trolls is the internet equivalent of getting a gremlin wet (and/or feeding them after midnight. Pick your poison.)
Trolls. Save your time and your energy for you. Don't feed the monsters.