There has been much debate in recent years about the role of non-state actors in international law. Whereas their presence is undisputedly acknowledged, their status and legal accountability remain unsettled. In many areas of public international law, harm is now significantly often caused by actors other than states. Terrorist groups threaten the territorial integrity of states; private security companies are involved in armed conflicts; individual hackers initiate cyber-attacks; and multinational corporations cause transboundary environmental harm or business-related human rights violations. Nonetheless, international treaties and customary international law still assign rights and duties almost exclusively to states.