A report compiled by NATO states that Internet-based attacks can be a legitimate form of attack in a war. The Tallinn Manual
on the International Law Applicable to Cyber Warfare, compiled by the NATO Cooperative Cyber Defence Centre of Excellence (CCDCOE) and recently published, applies the rules of war to cyber attacks sponsored by the state.
The first attempt at such a guide, the Tallinn Manual is likely to settle the legal disputes between countries that use cyberwarfare against each other. Though it is not an official NATO document due to it being a collection of opinions from security experts, it does explain how current international law can apply to online attacks, and states what could be permitted by both sides.
Notable points from the manual include the fact that an offline attack using weaponry is acceptable as a response against online attacks, if it is proved that the latter caused a sufficient amount of property damage or the loss of life. It goes on to claim that hackers causing the attacks can become legitimate targets for retaliation efforts, though the hacker's own attacks must avoid civilian systems and concentrate on those of the military or state.
In the last few months, the issues of cyberwarfare have been discussed by the White House and other government bodies, noting that the practice is on the rise. There are reports of a dedicated attack group
in Shanghai, operating out of a white 12-story office building, that is used purely to infultrate servers in other countries in order to access restricted information. The Obama administration in turn is applying
diplomatic pressure against opposing nations, as well as helping law enforcement in investigating attacks, and helping industries protect themselves.