Collective punishment is also practiced in the situation of war, economic sanctions, etc., presupposing the existence of collective guilt. Collective guilt, or guilt by association, is the controversial collectivist idea that individuals who are identified as a member of a certain group carry the responsibility for an act or behavior that members of that group have demonstrated, even if they themselves were not involved. Contemporary systems of criminal law accept the principle that guilt shall only be personal. Others view groups as being entities in themselves (an group), capable of holding guilt or responsibility independent of any of the group's members.