Sensing In/Security: Sensors as Transnational Security Infrastructures investigates how sensors and sensing practices enact regimes of security and insecurity. It extends long-standing concerns with infrastructuring to emergent modes of surveillance and control by exploring how digitally networked sensors shape securitisation practices. Contributions in this volume examine how sensing devices gain political and epistemic relevance in various forms of in/security, from border control, regulation, and epidemiological tracking, to aerial surveillance and hacking. Instead of focusing on specific sensory devices and their consequences, this volume explores the complex and sometimes invisible political, cultural and ethical processes of infrastructuring in/security.