How to respond to cyber attacks Israeli Defence Forces bombed a building allegedly housing Hamas hackers, after they had attempted to, according to the IDF, attack "Israeli targets" online. This is the first time a cyber attack has been met with physical force by a state's military. There is no consensus on whether a state is responsible for a cyber attack originating from its networks if it did not have explicit knowledge of the attack. This can be lawfully bypassed if a state can claim they're defending themselves against an "armed attack". The International Court of Justice explains that: "It will be necessary to distinguish between the most grave forms of the use of force (those constituting an armed attack) from other less grave forms." So a cyber-attack would justify force as self-defence if it could be considered an "armed attack". Only when the "scale" and "effect" of a cyber-attack are comparable to an offline "armed attack", such as attacks that lead to deaths and widespread damage to infrastructure.