Many think that it would be wrong to defend an individual from attack if he competently and explicitly refuses defensive intervention. In this paper, I consider the extent to which the preferences of victims affect the permissibility of defending groups or aggregates. These cases are interesting and difficult because there is no straightforward sense in which a group can univocally consent to or refuse defensive intervention in the same way that an individual can. Among those who have considered this question, (...) the dominant view is that that consent imposes only an extremely weak constraint on defending groups. I argue that this is mistaken and defend a much more robust requirement. Indeed, on the account that I develop there are cases in which the refusal of a single member of a victim is enough to make it impermissible to defend a much larger group. At the heart of my account is the idea that consent functions as an internal component of the broader requirement that defensive harms be proportionate: if a victim validly refuses defensive intervention, the fact that defence will benefit him cannot be used to justify harming innocents as the lesser-evil. An important implication of this view is that what constitutes sufficient consent from the members of a victim group will vary on a case-by-case basis. (shrink)