This paper discusses and explains a new penal phenomenon in the main Anglophone societies – the rise of the security sanction. Rather than reacting to crime, its purpose is to protect public safety by reducing the risk of future crime. It can be applied to both the most serious offenders and those who have not committed any crime. It can involve extended/prolonged terms of imprisonment and it can involve extensive restrictions on movement in public space. Its emergence can be explained by the post-1980s political, economic and social restructuring of these societies and the attendant uncaging of risk.