Couple of comments:
1. I know of weev from hacker circles. He really is this douchetastic. But what's really insane to me is that there's a bunch of women in the hacker scene who adore him. I couldn't quite understand it, until I saw them also adore Adrian Lamo, and so my theory is very close to Kathy's here: hero worship distorts reality. In order to stop people from enabling abusive trolls like this, someone has to debunk the hero status. Which is a lot more difficult than it sounds.
2. Being a troll is about one thing, and one thing only: power. The power to abuse someone and laugh and get away with it. The essential requirement of trolling is that you make someone upset. So there's a very real requirement that you do not respond in the way the troll wants in order for them to put their attention on something else. But trolls are varied, and sometimes they'll just keep plugging away at you. In cases like these you have to change tactics, though there's no guarantee anything will definitely put them off.
3. In general, trolls have goals. Usually it's to harass you until you literally disappear into the ether. Once they can't find any trace of you anymore, they have nothing left to do, and so they find another target. In this sense it's sometimes necessary to literally leave the [online or physical] community you face harassment in, or find a way to force the troll out of it. In either case it's basically a war, and you have to decide to either abandon the area or fight it out to the death.
4. I believe I understand why she was targeted. She has opinions that some people hate. Why, I have no frigging idea; ask a shrink. The point is, when people hate something, they lash out. And the internet is basically a hate delivery mechanism. And here's my opinion that will probably get me downvoted into hell: there is no way to stop this, other than leaving the internet.
Editorial rant (sorry about the length):
Being abused was not Kathy's fault. Unfortunately, you don't have to do anything at all to be abused on the internet. Just your picture, or a handle, or anything can be fodder for trolls. You can do absolutely nothing but exist and people will still try to abuse you.
In my opinion, from what I know of the internet, there is virtually no way to stop someone that hates you from abusing you here. There are no closed systems on the internet. E-mail is public, Twitter is intended to be public, but even if you make it private there's still a picture and a handle to start with (AND you can still direct tweets at private accounts), with Facebook you can avoid non-friends but not on comment sections, and on top of it all these accounts can be hacked. Private information like address, SS#, phone, etc can all be gotten incredibly, stupidly easily, without you ever going online. The internet is the easiest attack platform there is.
If you are visible in any way, you are a potential target for trolls, period. And I don't see any simple solution to any of this. We could re-design our internet services to protect people's privacy and anonymity better from abuse, but this wouldn't protect people who want to publish works like Kathy has. We could try to develop better tools to combat trolling, but that might become an arms race, who knows. Maybe we need to require a ss# and a picture ID for people to make accounts on social media. But regular accounts might just get hacked to be used as sock puppets.
So perhaps there is no technical solution. Perhaps we just need to change the way our entire society treats itself, both online and off. Peacefully boycott sources of abuse, negativity, ridicule and scorn online (i'm looking at you, every-forum-on-the-internet). Combat the causes of insecurity and fear and hate. Provide more social services to support the emotional welfare of all people. Something other than band-aids and coalitions. Maybe it'll never happen in our lifetimes, but at some point we've got to sit down and figure out a way to encourage people to be compassionate, or we're all doomed in the much larger picture of world-wide human affairs.