Little Brother by Cory Doctorow. Suppose I purchased tackle at a gun shop then an airline ticket? Would I get a ‘call’? A visit?

Little brotherSeventeen year old Marcus and his friends witness a terrorist bombing in San Francisco, and get arrested as suspects by the Department of Homeland Security. On his release, Marcus is terrified but resolved to help his friends. A deft hacker, he sets up an underground resistance movement online, ultimately becoming a hero in the fight for freedoms he had taken for granted all his young life. This quick-paced work of fiction is geared to younger teens, but also a fun introduction to the technology of security and the privacy issues at stake.

Take Bayesian analysis. Marcus takes an aberrant bus ride, and gets picked for questioning in the hopped up police state following the attack. His dad, an information expert, explains that Bayesian analysis is used all the time to find anomalous events. A profile of an average event is created, and then a computer can find records that are furthest from the average. It is useful for spam filtering. What else can it do? A co-worker told me his credit card company called him when they detected a suspicious purchase combination – a large screen television followed by gas. Apparently this combination is almost always fraudulent. Quite handy in that case. But what if I made a purchase at a gun store then bought an airplane ticket? I was only buying tackle and a flight for my fishing trip. Would I get a call? Would I get picked up?

There is a worrisome tradeoff between security and privacy. When I visit the public gallery at the House of Commons, I have to go through security and metal detectors twice. I was curious when a friend’s gum got confiscated — apparently they do not want you throwing things at MPs. Somehow my gum got through. My job takes me through airport security twice a week at present. Do these invasions of privacy work? Maybe a little, but I think the real intent is to create a public perception that something is being done. Is it worth it?

Books like this make a difference, not just in the questions they raise but also in the hacker skills they inspire. ParanoidLinux is a fictional operating system in the book, designed to protect anonymity, but real-life hackers have begun work on one. Neat!