This last intuition has attracted considerable attention. While it seems intuitively proportionate to kill several culpable lethal attackers, many find it unacceptable that there is no limit on the number that may be killed. This implication seems particularly hard to swallow in the case of attackers who, though liable, are not fully culpable. But there is considerable theoretical difficulty in justifying such a limit. If, considered in isolation, each of the multiple attackers meets the conditions for liability to be killed, then it is hard to see how defensive killings that are each (narrowly) proportionate can somehow become disproportionate when aggregated. As Frances Kamm puts it: