The Internet in its current state is similar to a city with no locks on doors of its houses, where computers can be thought of as houses and networks making up Internet, city streets. Computers as they are sold today are inherently insecure, allowing access to anyone with a bit of curiosity or malicious intent. As businesses come to rely more and more on electronic information (not least e-mail), potential disruption caused by a data burglary, informational arson attack or digital graffiti has reached a level that businesses should not ignore

The threat Any computer on Internet exposes a series of ports through which information flows. By default these are all open and unlocked. Whilst many of them may lead to empty rooms or brick walls, an attacker will only need to find one port vulnerable to attack for whole system to be compromised.

Even if your ports are secure; intruders can get into your computer in a Trojan horse. A piece of software disguised as something useful can contain a malicious sub-program to install a backdoor into your system. Often these programs claim to give something for free or display small games whilst an attacker has a good nose around

One of most worrying developments has been proliferation of automated attacks. These can be run from an attacker's computer, scanning hundreds or thousands of computers in a day; or can be self-replicating Internet worm. These are a hybrid of virus programs and computer security attacks. In worst-case scenarios, they can bring whole segments of Internet to a standstill.

Attacks on your information can be carried out for as varied reasons as an arsonist burns things, a robber steals things or kids spray-paint walls. An electronic attack could leave you with no data (imagine losing your accounts day before your filing date), data that has been altered in subtle ways (imagine your accounts with 10% taken off each figure), a website that is 'owned' by a teenager in another country or an office full of computers that no longer do job for which they were intended.

When we drive a car we are accepting and using a set of standards that have evolved since turn of century to ensure safety, convenience and fair access for all users of road system. Some of these standards are globally accepted (for instance a road is made from tarmac and wheels are made from rubber) whilst others vary from country to country (for example if we drive on left or right). The practical upshot of these standards is that a car designed and built for use in one country can be safely used in another (possibly with a little bit of inconvenience).