One passage that caught my attention in Little Brother was the explanation of false positives and why they cause so many problems in systems like the terrorism detection in the book. For some things, a test that is 99% accurate works great. However, if the test is trying to detect something that is very uncommon in a very large group—such as people who are terrorists, which the book estimates as making up 1/20,000% of a city’s population—then that 1% of inaccuracy begins to cause a huge problem. In a city like San Francisco, with 20 million people, incorrectly identifying 1% of the population as terrorists means investigating two hundred thousand innocent citizens—in order to maybe catch ten terrorists. And, as such a system would likely be far less than 99% accurate, the problem would be far worse.
Things like this are important to take into consideration in today’s society, which is becoming ever more concerned with security and devising new ways to prevent terrorist attacks—even if it means invading people’s privacy. While programs such as the one in the book are not currently in place in America, if an attack like the one on the Bay bridge were to occur there would likely be support for implementing them. However, there comes a point at which, in the name of “defending freedom,” freedom is actually taken away, and that’s something we need to be very careful of.