THE US AND ISRAEL COVERTLY TARGET IRAN, WITH 'STUXNET' & 'FLAME'

Now widely categorised as the world's first cyber weapon, the 'Stuxnet' worm was designed by the US in tandem with Israel to wreak havoc in an Iranian nuclear installation in Natanz. Unleashed in 2009, it apparently succeeded to some extent before it got out and infected computers across the world. Stuxnet has even been dubbed a "Hiroshima moment" by some commentators, and it's success may have triggered a global cyber arms race. Other cyber weapons like 'Flame' and 'Duqu', which also appear to have targeted countries in the Middle East antagonistic to the US and Israel, were designed to be stealthy intelligence collection programs. Uncovered by security experts only last month, Flame, most say, is the sophisticated result of a complex and highly professional effort to develop such a program - not the work of mischievous hackers.

RUSSIA AND ITS 'CYBER MILITIA' ATTACK ESTONIA AND GEORGIA

When Russia and Georgia fought a brief war - over a disputed border - in 2008, many analysts believe the Russians may have blazed a new trail by incorporating cyber warfare tactics into military strategy. Russian hackers infiltrated Georgian government networks weeks before actual 'kinetic' military operations began, and then launched huge denial-of-service attacks to bring down all Georgian network infrastructure when the tanks finally began to roll in August. These cyber attacks were also designed to prevent Georgians from using the net to garner international sympathy. In 2007, another neighbour, Estonia, was targeted by Russia's cyber militia when a row broke out over Estonia's relocation of old Soviet icons. Major government and financial websites were targeted, while Estonia's internet network was clogged to the point of collapse. These ostensibly 'unofficial' attacks lasted 22 days and saw the Kremlin being slammed, but not officially blamed, by Estonia. '

TITAN RAIN', 'NIGHT DRAGON', 'GHOSTNET': CHINA'S AGGRESSIVE SPYING ON THE US

Besides being evidently proud of the fancy names bestowed on such attacks, China's vast legions of hackers appear to have a long history of launching aggressive cyber espionage operations on targets in the US, especially its military networks. Several largescale cyber attacks (of mostly Chinese-origin ) on government agencies and big US corporations have occurred between 2005 and 2011. The most recent instance was a coordinated series of attacks in 2011 that targeted major US oil firms in which significant amounts of sensitive data were siphoned off, as is usually the case in such successful ops. The US military's Cyber Command chief indirectly accused China's intelligence services of being responsible last year. Many of the corporations targeted have also pointed fingers at Beijing. In 2010, Google loudly complained of 'sophisticated cyber attacks', which the company said originated in China. Wikileaks later revealed that US diplomats believed the operation had in fact been ordered by top government leaders.