Little Brother, about a teenage's boy's fight against an excessive crackdown by the Department of Homeland Security after a terrorist attack in San Francisco. I read a negative review on Amazon which rightly complained about the cookie cutter bad guys and lack of evidence that our hero is such a great hacker, but I still think they sort of missed the point.
As I've been worrying about the world and dread reading the news, I am often given hope by hackers and visionaries who might have looked like the protagonist when they were a few years younger. These are people who hold dear the ideals on which this country was founded--rights to privacy, freedom of press, expression, assembly, religion, and to be treated fairly and equally before the law--and who have the technological power to defend them. I love passing that hope on to my daughter when she asks me, "Why do they do that?" in response to the news of some corrupt government official.
She's actually the intended audience for this "young adult" book, and she really liked it, calling it "very intense". I highly recommend reading it yourself and then sharing it with your kids. We need to have hope.