Trolls are yesterdays news, though they will be making news for a looooong time, mostly because they are either trolling to inspire others to follow them(hello terrible person who needs people to follow them more than they need actual attention from real people), or because they actually believe it(hello even more terrible person who actually believes what they say).
A study that says that trolls are terrible is like a a study that finds that criminals can be actually quite mean at times, or the use of water can make things wet.
And to be fair, we don't really understand trolls. I know I'm gullible. It seems like they might have a new idea there, or something viable. I actually had someone accuse me of trolling my own Facebook page. I mean really, like wait what? My page? How can I troll it? Because I disagree with something doesn't make me a troll. OR DOES IT.
Trolls are yesterdays news - grotesque memories of a time in which the internet was young and privacy was still attainable. We'll probably lose that at some point. What does the future hold for new and awful ways we can embarrass ourselves and take others down with us? Trolls are the snake-oil salesmen of today, the con-men who lure you in with the idea that their ideas might be interesting, cutting edge, but who are really just looking to make a buck.