From the ICRC to the Tallinn Manual on International Law Applicable to Cyberwarfare, there seems to be a broad consensus that cyberwar, like any other method or means of warfare, is subject to the traditional rules of the law of armed conflict, including one of its ‘cardinal principles’, the principle of distinction. However, the transposition of the principle of distinction into cyberspace raises important legal questions. Indeed, the prohibition of direct attacks against civilians, which is the cornerstone of the principle of distinction, cannot be easily transposed to cyber-operations that are in part or completely dematerialized. It is thus necessary to review this principle carefully in order to assess whether it is strictly focused on the prohibition of ‘attacks’ against civilians or whether it could also be interpreted as prohibiting any kind of direct military cyber operations against them. The interconnectivity characterizing the cyberspace also challenges the protective status given by the principle of distinction. By blurring the distinction between civilians and the military, cyberwarfare makes the enforcement of the principle of distinction all the more challenging.