People don't understand computers. Computers are magical boxes that do things. People believe what computers tell them.

Think of your existing power as the exponent in an equation that determines the value of information. The more power you have, the more additional power you derive from the new data.

ID can be hijacked, and cards can be faked. All of the 9/11 terrorists had fake IDs, yet they still got on the planes. If the British national ID card can't be faked, it will be the first on the planet.

Hardware is easy to protect: lock it in a room, chain it to a desk, or buy a spare. Information poses more of a problem. It can exist in more than one place; be transported halfway across the planet in seconds; and be stolen without your knowledge.

Anyone, from the most clueless amateur to the best cryptographer, can create an algorithm that he himself can't break.

It is poor civic hygiene to install technologies that could someday facilitate a police state.

It's frustrating; terrorism is rare and largely ineffectual, yet we regularly magnify the effects of both their successes and failures by terrorizing ourselves.