All four are detained and questioned for several days as suspects in the attack. Marcus' interrogation is particularly severe; he is finally released along with two of his friends, but the injured Darryl has disappeared. Warned not to tell anyone of what happened to them during their imprisonment, the friends re-enter a city that has been placed under repressive surveillance in response to the attacks.

Humiliated by his own capitulation to his captors, enraged by the tactics of the government and unable to trust any adults to aid or believe him, Marcus vows to fight the Department of Homeland Security using what he knows best: computer technology. Under the nom de guerre "M1k3y," he begins an insurgent campaign using the heavily encrypted "Xnet" to disseminate false information and thereby disrupt the authorities' ability to monitor the population. He finds a groundswell of support, especially among young people—"Don't trust anyone over 25" becomes a rallying cry within the new movement—but every apparent victory results in unexpected collateral damage and is met by increasingly harsh responses from the government.

When Marcus finally learns the fate of his missing friend Darryl, he is forced to seek help from the adult community, help that could finally reveal the government's abuses of power in the wake of the terrorist attacks—but that may not be able to shield Marcus from the wrath of the DHS, which is determined to put "M1k3y" away once and for all.

Control machines, not the other way around

Little Brother is a number of different books at once. Its titular evocation of George Orwell and grim rendering of a totalitarian crackdown places it firmly in the tradition of dystopian literature, while its willingness, indeed eagerness, to pause for frequent lectures on the details of computer networks and information security places it equally firmly in the classic tradition of hard SF. And, of course, the fact that the novel is specifically labeled "young adult fiction" imposes yet another set of expectations as the nightmare scenario narrated by Marcus focuses, inevitably, on the concerns and worldviews of the teenage narrator and his youthful cohort.

Does it all come together? For the most part, impressively so. Doctorow's comprehensive knowledge of contemporary information technology combined with his palpable anger at the excesses of the post-9/11 surveillance state make for a story that leaves the reader thinking, "Yes, that's exactly how that would happen—oh, wait a minute, it's already happening!" And both Marcus' voice and the voices of his peers are pitch-perfect; the book is at its best in scenes, such as a richly evoked unsanctioned concert, that capture the pure energy and potential of youth.

Doctorow's flawless representation of his youthful narrator is also, arguably, the source of some of the problems adult readers might have with the novel. While the teenage characters are utterly convincing, the adult characters are somewhat less so, and Marcus' various debates with parents and teachers too often feel both static and contrived. Though much of the book, Marcus combines the narcissism of the highly intelligent teenager with the arrogance of the hardcore programmer. Early on in the proceedings, he seems more upset that his laptop has been bugged by the government than he is about the thousands of deaths that resulted from the terrorist attacks; at one point he declares, "If you've never programmed a computer, you should ... if you want to be in charge of your machines, you have to learn to write code." His best friend refuses to be a part of his activities because she believes he is dangerously indifferent to the consequences his actions have for other people. By the end of the book, Marcus has realized and acknowledged many of his mistakes, but the adult reader—especially the adult reader who is also a parent and/or teacher—may be forgiven for wondering whether Marcus has really gained the level of self-knowledge and awareness of others that he will need to be a fully functioning adult.

But that same dubious adult reader may then watch the evening news and, realizing what a dangerous road the United States has traveled down in recent years, be impressed all over again that Cory Doctorow has dared not only to say what is wrong and how it might be dealt with, but to say all of this to precisely the audience that most needs to hear it: the young people who will grow up and run the world. In that sense, Little Brother is one of the most important SF novels of the decade and well worth the attention of readers both young and adult.