Moral responsibility scepticism, understood as taking seriously the possibility that we lack the kind of control in our actions to be truly deserving of blame and praise, raises concerns about how we can justify punishing criminals. If no one deserves blame, on what basis can we sanction criminals? The Quarantine Model by Derk Pereboom is one proposal that offers a possible justification. It draws on an analogy between carriers of severe infectious diseases and dangerous criminals: in the same way that we may be able to justifiably quarantine blameless individuals carrying dangerous diseases for the purpose of self-protection and the prevention of harm to others, we could similarly justifiably “quarantine” dangerous criminals for the purpose of self-defence and defence of others, even though such individuals are blameless according to moral responsibility sceptics. In other words, this model appeals to the right to harm offenders in self-defense and defence of others to justify criminal sanctions. But there are questions about whether such a model can adequately deter criminal behaviour. In fact, some have argued it might incentivize crime. I explore the limits of the right to harm defensively and argue that it could be used to justify deterring punishments under some circumstances.