Some of the moral and ethical issues in The Girl with the Dragon Tattoo are straightforward: Nazism = bad; murder, rape, torture, physical abuse = bad; global financial fraud and organized crime = bad. But it's what happens while Salander and Blomkvist try to fight such evils that presents us with a variety of moral and ethical dilemmas. Salander and Blomkvist both have serious moral codes but they sometimes disagree about ethics and methodology. Salander has absolutely no problem prying into the lives of others. Like many fictional vigilantes, from Batman to Charles Bronson in the Death Wish movies, she fights the bad guys with their own tools. And that means violence. Blomkvist is faced with the moral and ethical dilemma of his life when he's asked to agree to the cover up of Martin's crimes, to save Harriet and the Vanger Corporation from public disgrace. Since Stieg Larsson dedicated his life to social activism, it's no surprise that morality and ethics are a central theme in his novels.