The conduct of hostilities via cyberspace poses many issues regarding the application of international humanitarian law. Cyberspace should be considered as a sui generis battlefield when it comes to the study of the applicable law. The present contribution aims to identify some of the key issues arising from the application of the law of targeting to cyber operations in the context of an armed conflict, focusing exclusively on the application of the principle of distinction. The principle of distinction - the cornerstone on which humanitarian law stands - today is shrouded in uncertainty in the context of cyber operations. The key threshold of attack, the definition of military objective and the targeting of dual-use cyber infrastructures and digital data are some key issues that need to be further developed in the context of cyber operations. Finally, with regard to targetable individuals, the status of cyber combatants, cyber levée en masse and the notion of direct participation in cyber hostilities, are underdeveloped legal concepts and need particular interpretation in the context of cyber operations. The complete lack of international jurisprudence and the embryonic state practice on the emerging field of cyber warfare call for the principle of distinction and the relevant provisions of lex lata to be assessed on a humanitarian basis and reconceptualized in light of the warfare reality.