Death Note is a 37-episode anime series about a student, Light Yagami, who finds a notebook that gives him the supernatural power to kill anyone whose name and face he knows. He then goes about destroying criminals who commit aggression against others, and the police who get in his way, in an effort to create an ideal world. As with many comic books, TV series and films involving superheroes with special powers, the philosophical question of whether government should have a monopoly on violence, or whether private individuals, acting in a vigilante capacity, should be able to enforce natural law on their own, is examined. From a consequentialist, and perhaps even a deontological point of view, one might regard it as immaterial who is the enforcer of law, as long as the enforced law is just and beneficial.
The assumption that, for all practical purposes, might is right — or at least that might must be submitted to — is summed up in Light's statement, "If Kira is caught, he is evil. If Kira rules the world, he is justice. But the world is rapidly coming to Kira's side. Soon Kira will be justice."
People tend not to denounce and rail against a force that is so powerful that there is no resisting it; they acquiesce because there is no other choice. Arguably, the only reason libertarians bother to speak against evil is that they hope they can eventually overthrow evil. Otherwise, there would be little point in complaining; it could even be counterproductive, since the only use of resisting power is to attempt to tear down that power, partially or completely. Cooperation is more productive for society unless there is something to be gained by refusing to cooperate.
One of the characters, Teru, defends the weak from bullies based on his belief that "Evil has to be confronted." When he returns home bruised, his mother tells him, "Teru... Not everything in the world works the way you want it to. Please stop. There's no reason for you to be bullied. There's no reason for you to be hurt like that. You'll just look foolish. Nothing will change, no matter how hard you try..." He concludes that she is wrong, and persists in his crusade against evil.
Light is told by his nemesis, "You are just a murderer. And this notebook is the worst murder weapon in history. . . . You're just a crazy serial killer who has confused himself with a god. That's all you are. Nothing more, nothing less." This statement is rather ironic in light of the government's belief in its sole prerogative to exercise supreme power and its willingness to execute those it designates as capital criminals; or, in the case of life imprisonment, to hand down a sentence that deprives a person of the liberty he would have needed in order to enjoy life or contribute to others' enjoyment of life, which thus functions much the same as a death sentence.