This problem is already solved. It's called the "ignore user " button. Push it and you no longer see the posts from the offending troll. Troll can see your posts, but you can't see theirs. So troll has unpleasant (for a troll) experience of seeing a conversation carried on as though what he was posting simply didn't exist, because it didn't for anyone who regarded him as a troll.
If a troll is like porn, we know it when we see it, then this solution works very well. Everyone sees and ignores the troll, depriving the troll of their motivation for trolling in the first place.
The only problem we have is sites don't use the available technology.
I have been on sites where this virtually eliminated the troll problem. Of course the automated accounts that are spamming viagra require something else, but that is not what the article was complaining about. The article was complaining about civility.
I really have to wonder if there are ulterior motivations at work here. Trolls are the new "we must save our children" rallying cry, an argument designed to force people into ID ing themselves, tagging themselves as "legitimate" so they can be better tracked and monetized. I feel like these pieces are set pieces, ready to roll out as soon as their beneficiaries and creators think their might be some temporary, rising sentiment against anonymity on the web.
Current example- Robin William's daughter's recent Twitter experience.
Sure, a troll gets one off but that is all anyone will see of him.
There is no free speech without anonymity and giving it up because some asshole made someone cry is ceding my freedom to assholes. That wont' be happening.