Monsters remain human beings. In fact, to reduce them to a subhuman level is to exonerate them of their acts of terrorism and mass murder — just as animals are not deemed morally responsible for killing. Insisting on the humanity of terrorists is, in fact, critical to maintaining their profound responsibility for the evil they commit. And, if they are human, then they must necessarily not be treated in an inhuman fashion. You cannot lower the moral baseline of a terrorist to the subhuman without betraying a fundamental value.