Trawling the Wires: Mass Surveillance of Border-crossing Communication in Denmark during World War II

The article examines government censorship and surveillance of transnational communication in times of war and crisis. At the center of analysis is the monitoring of border-crossing telephony in Denmark during World War II. The system expanded decidedly during the war, in terms of staff and equipment, bureaucratic record-keeping and the forms communication deemed eligible for monitoring. Communication across borders had been perceived as a potential security problem already before September 1939. Yet the context of war made the problem grow in gravity from potential to very real, and people who communicated across the national borders became suspicious through the very act of communicating. Thus, increasing amounts of information were accumulated in an increasingly complex collaborative project between the Danish P&T, the Foreign Ministry, and the German security service Abwehr—information on citizens, foreigners, firms, and news agencies, but also on capital flows, propaganda schemes, and tendencies in foreign media reporting.