Both Cerf and his wife, Sigrid, have hearing impairments. Cerf wears two hearing AIDS that enable him to not rely on lip reading or sign language.

I dedicate this book to my wife Sigrid and to my ten-year-old son Wolfgang, who helped me to write the computer program producing Fig. 7.1.

Sigrid Rausing, a top British donor to human-rights causes, says she regrets the “blurring” of the original mission: “There are so few organisations that focus on individual prisoners of conscience.”