A pivotal moment in cyber-security history was the discovery of Stuxnet in June 2010. This 500-kilobyte worm was found to have destroyed one-fifth of Iran's nuclear centrifuges, which set back Iran's nuclear program by some years. This type of malware threatens the security of information for businesses, individuals, and governments. Former US Defense Secretary, Leon Panetta, warned that the US is vulnerable to a "cyber Pearl Harbour" that could derail trains, poison water supplies, and cripple power grids. The size of the cyber-security market is large and is expected to grow at a rate of 12-15% per annum to a projected size of US$75 billion by 2020. Two Australian small-cap stocks operating in the sector are Senetas Corp (SEN) and Prophecy International Holdings (PRO). Read the full article for more information on cyber-security and a brief discussion of some of theways to gain exposure to the theme.