Studying technology use in unstable and life-threatening conditions can help highlight assumptions of use built into technologies and foreground contradictions in the design of devices and services. This paper provides an account of how soldiers, volunteers, and civilians use mobile technologies in wartime, reporting on fieldwork conducted in Western Russia and Eastern Ukraine with people close to or participating directly in the armed conflict in the Donbas region. We document how private mobile phones and computers became a crucial but ambiguous infrastructure despite their lack of durability in extreme conditions of a military conflict, and their government and military surveillance potential. Our participants rely on a combination of myths and significant technical knowledge to negotiate the possibilities mobile technologies offer and the life-threatening reality of enemy surveillance they engender. We consider the problems of always-on, always-connected devices under conditions of war and surveillance and our responsibilities as HCI practitioners in the design of social technologies.