Who's expense should it be then, in your opinion, to pursue (civil or criminal) legal action against the "troll"? AFAIK, if she wins, she can also demand payment of legal fees, so it's really just her time that's at stake.
2) As Cory Doctorow put it "Never underestimate the determination of a kid who is time rich and cash poor." demanding payment of legal fees from someone who has no money doesn't get you very far.
3) The question is whether there is a societal problem here that we should care about at the level of governance. I'd argue yes, but what the remedy should be is way more complicated a topic, and something that i think is probably only worth discussing in good faith. So if you don't think this is a problem, that should be addressed first.