 Policies that interfere with conduct that does not produce direct harm to others are sometimes criticized as government overreach in virtue of failing to satisfy the harm principle (Jones and Bayer 2007; Quong 2011; Flanigan 2014b). For instance, opponents of motorcycle helmet laws in Massachusetts explicitly invoked Mill when pressing their case in court (Jones and Bayer 2007, 211). Conversely, the harm principle is invoked to justify policies where harm to others is a paramount concern, paradigmatically for various infectious disease control interventions such as quarantine, isolation, and compulsory treatment (Flanigan 2014a; Holland 2007; Navin 2016; Giubilini 2019). In liberal democracies, the harm principle is often viewed as the most compelling justification for public health policies that interfere with individual liberty. For example, some claim that in the United States it was not until the public became persuaded of the harmful effects of “second-hand smoke” that the first significant intrusion into smoking practices – the banning of smoking in public places – became politically possible.