It could be argued that all computers connected to the Internet can be, to one degree or other, considered part of the State's computer critical infrastructure. This is because the Internet enables every computer to be connected to every other computer regardless of its size or the job it does.

For example, a home computer can connect to a large financial corporation's mainframe computer or to a government department's computer or a university's computer. As such, if a home or small business computer is effected by a terrorist attack (for instance, through a virus), there is the possibility that damage could spread very rapidly through the Internet to these other computers.

If the State's computers are disabled, not only will it affect commerce and industry, peoples lives could be placed at risk as many medical facilities rely heavily on computer technology to deliver their services.

How to prevent cyber-terrorism

Although there are no foolproof ways to protect a computer (other than disconnecting it from the Internet), there are four simple steps that all South Australia's who own or use a computer can take to help prevent a cyber-terrorist attack.

• Step 1: Install and use a "firewall" when connected to the Internet;
• Step 2: Download and install updates for your computer's operating system;
• Step 3: Install and use anti-virus software and download viruses definitions (at least once a fortnight); and
• Step 4: Install and use "anti-spyware" software and download definitions (at least once a fortnight).

Installing a firewall (either a software firewall or a hardware version) will provide a very high degree of protection to your computer by making your computer "invisible" on the Internet. This does not stop you from sending and receiving emails or browsing the Web. But it does stop terrorists and anyone else from randomly searching the Internet for computers to try to hack into.

Downloading the most up-to-date operating system patches ensures that any potential vulnerability that has been discovered and might be exploited by a terrorist are closed-off -- like locking an otherwise open door. These are available from the operating system developer (for instance Microsoft,^® Apple^® and Unix,^® etc).

Installing an anti-virus software will help guard against malicious programs that have been sent as part of a cyber-attack through email or downloaded for a Website. It will also help stop the spread of destructive code to other computers on the Internet should your computer be infected - in a sense, quarantining the damage.

Installing an anti-spyware program will help prevent terrorists from gathering information about your computer without your knowledge, and using it to plan a cyber-attack. Spyware is installed secretly on your computer through programs innocently downloaded off the Internet and records passwords and other confidential information that could allow a terrorist to "steal" and use of your computer as a base to launch an attack - like stealing a car to use as a car bomb. Spyware programs can track your online and/or offline computer activity and are capable of transmitting that information to the perpetrator covertly.