5 years ago: Fraud costs UK firms £5bn per year

17.05.99: Internet fraud costs UK businesses £5bn per year, according to the Fraud Advisory Panel, part of the Institute of Chartered Accountants.

Among the causes: the introduction of the euro and growth of trade over the net. Companies getting online for the first time are also contributing to the problem, as they're more likely than experienced companies to leave holes for fraudsters to exploit.

17.05.04: Online fraud is still a huge concern, though firms have had years to secure their sites and services. Fraud continues on the web, it seems, because users have not yet come up to speed on all the dangers that await them.

'Phishing' scams, whereby con artists send out fake emails that look they're from banks or online retailers, are among the most common. The messages ask users for confidential information and many give it up, thinking they're communicating with a trusted source.

These scams are on the rise across the globe - recent research from Gartner shows one in five Americans were the target of a phishing expedition in the past year.

It's not just bad for users; it's bad for business too. A recent survey carried out by telecoms firm Energis says that customer attrition in the business-to-business sector grew by 47 per cent after a firm fell victim to a hack attack, virus or phishing fraud. In the UK, rival firms often use such an event as an excuse to switch suppliers.

Of the 100 companies Energis spoke to, nearly all of them had experienced a security breach over the past year - which means loads of lost revenue that could have been saved, had the firms secured their systems.