However, Thomson’s reliance on causal roles makes it hard for her to prohibit harming at least some innocent people whom she herself considers it impermissible to harm. Plausibly, someone who maliciously blocks Victim’s escape from a fire is liable to defensive harm. If Thomson grants this, she must also grant the permissibility of harming a person who innocently blocks one’s escape (Frowe 2014a: 25–26). If the malicious obstructor plays the right kind of causal role to violate Victim’s rights, and violating rights does not require agency, then both innocent and malicious obstructors must be liable to defensive harm. Yet Thomson, in line with most people’s intuitions, explicitly rejects the permissibility of defensively harming innocent obstructors (Thomson 1991: 290).