Nyongesa, thanks for your post, which is quite noble but I think life is often more complicated. 

The books I mentioned are thrillers involving serious crimes like murder, sexual assault, kidnapping et cetera and so I'm quite sure (as with a movie) that we'd all be rooting for the bad guys to meet a bad end. But even in everyday life it's not necessarily a good strategy to simply "clean one's soul."

Let's suppose, for instance, you are in a meeting at work and your boss takes credit for your idea in a way that will boost his career and destroy your own. You don't have the luxury of doing nothing, unless you are independently wealthy. How do you respond?

We could come up with more serious examples. Our world is full of violence and also full of acts which, while not quite evil, are none the less misguided and wrong. I think there is a certain duty each of us has to actively make the world better by fighting corruption, creating safe space, standing up for each other, et cetera. I also think it's crucial to avoid victim mentality, as you suggest, but this does not mean not acting.

That said, however, the manner in which we go about confronting wrong acts differs enormously from person to person. Some people want the objective satisfaction of a judge and jury. Others put up with this system because that is what society endorses, but they would really like nothing more than to take justice into their own hands: "Don't ever cross me again." I might even say the difference is whether a person would like the wrongdoer, at the end of the day, to believe that what s/he did was wrong, or to understand that it was wrong and moreover s/he should never have tried to mess with this person.

I don't know you well, just from a few posts, but are you really saying you're not of the second opinion?

Penelope I get the sense you're ambivalent about the romanticization of vigilante justice as embodied by the character of Lisbeth Salander. I'm not entirely sure how I feel about that myself. I only know the stories from the movies (haven't read the books) and  I enjoyed them for what they were, but I don't think I took them seriously enough to have a strong reaction to the moral universe they inhabit. Maybe my reaction would be different if I had read the books. 

Anyway, here's my take on the stories. In an age of cynicism in which faith in traditional authority figures and power structures has evaporated many people come easily to the belief that the only justice to be had is the kind you are willing to take for yourself. Popular culture lionizes the outsider who lives by his own rules and isn't shy about using violence to break through the "phoniness" of ordinary life in order to attain transformative ends. When you think about it the whole Tea Party movement is built on exploiting that archtype. It seems to me Steig Larsson is very much working within that tradition, with the significant difference that he has appropriated the role for a female protagonist (the Swedish title of The Girl with the Dragon Tattoo is actually Men who Hate Women. I leave it to you to imagine why the publisher felt the need to change the title for a predominantly American English reading audience). The rest is mostly writer's artifice. I very much doubt any real person could do the things Lisbeth Salander does (or if they did, get away with it) but as a fictional character Lisbeth's accomplishments are only limited to her creator's imagination. That gives her an incomparable advantage over you or I! Also, Steig Larsson is smart enough as a writer to know that while moral ambiguity is ever present in the real world, it's not what people are looking for in escapist entertainment. Lisbeth does some pretty brutal things in the stories, but always only to people who are truly irredeemably bad (and are shown to be so in very graphic ways) and who therefore "had it coming". In keeping with the conventions of the genre Lisbeth's actions are made to seem more reasonable because the authorities are either incompetent (e.g. the police) or corrupt (as when she is sexually abused by her guardian).

Some people have held up Lisbeth as some sort of feminist icon, which I think is really going too far, but if you accept the stories on their own terms they're fun in a "don't try this at home" sort of way.