A new kind of warfare

In a speech recently on Internet freedom, Hillary Clinton said: "Countries or individuals that engage in cyber attacks should face international condemnation," alluding to the China-Google kerfuffle.

Botnet threat
An important weapon in the cyberattack arsenal is a 'botnet', a cluster of thousands and sometimes millions of compromised computers under the ultimate remote control of a 'master'. Botnets were behind last summer's attack on South Korean and American government websites.

They are also engines of spam that can deliver destructive malware. The United States has nearly the most infected botnet computers and is thus the country from which most botnet attacks stem.

Hacktivist fight
The United States is also a leading source of 'hacktivists' who use digital tools to fight oppressive regimes. Scores of individuals and groups design or employ computer payloads to attack government websites, computer systems and censoring tools in Iran and China.

These efforts are often supported by foundations and universities, and by the federal government.

Under (cyber)attack
The US government has perhaps the world's most powerful and sophisticated offensive cyberattack capability, that remains highly classified.

But The New York Times has reported that the Bush administration used cyberattacks on insurgent cellphones and computers in Iraq, and that it approved a plan for attacks on computers related to Iran's nuclear programme.

These "warriors" are now under the command of the National Security Agency, the world's most powerful signals intelligence organisation.

Simply put, the United States is aggressively using similar techniques for ends it deems worthy. On the private side, hacktivism can be a tool of liberation. On the public side, the best defense of critical computer systems is sometimes a good offense.

But in a survey published recently by the security firm McAfee, information technology experts have expressed concern about the United States as a source of more computer network attacks than any other country.

This awareness fuels a dangerous public and private cyber arms race in an arena where the offense already has an advantage.

Creating norms to curb cyberattacks is difficult enough because the attackers' identities are hard to ascertain.

But another large hurdle is the federal government's refusal to acknowledge more fully its many offensive cyber activities. Washington Post-Bloomberg.

- The United States is the source of more computer network attacks than any other country.