Back when our lives were not dominated by digital communications, eavesdropping on someone was expensive because it required people to do it. Letters had to be opened and copied. Microphones and tape recorders had to be discretely installed to record conversations. In the past twenty years things have changed, however: the number of intermediaries we use to communicate with one another has exploded, and surveillance is now automated. Not a year goes by without headlines in the news reminding us how much the State or corporations take advantage of these technological developments (and related changes in society) to exploit the private data of citizens, human rights defenders, and journalists.