Earlier quoted context omitted.
Even then, it’s all the more important to find the questions with the highest entropy, given that you know someone’s already in a popular group. It’s all about evenly dividing the population based on important factors. Evenly dividing people is easy enough, and finding important factors is easy enough, but doing them both at the same time can be very tricky.
> Even then, it’s all the more important to find the questions with the highest entropy Also see http://www.gwern.net/Death%20Note%20Anonymity for a discussion of information theory in identifying people.
As an aside, I'm now worried about serial killers trained in using information theory to prevent themselves from being caught. Although not having a supernatural Death Note makes that a lot more difficult.