This paper examines the interaction of law and policy making on prostitution, with that of BDSM (bondage and discipline, sadism and masochism). Recent policy and legal shifts in the UK mark out prostitutes as vulnerable and in need of 'rescue'. BDSM that amounts to actual bodily harm is unlawful in the UK, and calls to decriminalise it are often met with fears that participants will be left vulnerable to abuse. Where women sell BDSM sex, even more complex questions of choice, exploitation, vulnerability, power and agency might be thought to arise. Does the combination of activities take two singular behaviours into the realm of compound harm? Are those who sell BDSM doubly vulnerable in a way that would justify criminal intervention? This paper argues that in imposing categories of vulnerability, the state engages in the heteronormative construction of risky sexual subjects who must be rehabilitated, responsiblised or punished. Through an examination of existing empirical studies on BDSM, the paper offers a feminist critique of the potential criminalisation of commercial BDSM and calls for more research on the lived experiences of those who buy and sell BDSM.