It's been a bad week for some of the giants of the Net. Yahoo, the biggest site on the World Wide Web, was crippled by information overload, orchestrated by hackers. It was not alone. Amazon.com, E*Trade, Datek, eBay, CNN and Buy.com, all fell victims to the attacks.

The offensive illustrates the frailty of even the most advanced sites in protecting themselves from attack by hackers using what investigators say are widely available hacking software which could be operated by teenagers.

Essentially they programmed a number of unwary computers to bombard the sites with so many bits of information or requests that regular users were unable to access the sites, despite security features that are supposed to prevent precisely such attacks.

The trouble is not that customer details or financial records were compromised - they weren't - but that the burgeoning e-commerce revolution needs the confidence of consumers that it is free from the threat of such attacks before it can truly join the mainstream.

The sooner the hackers - apparently more mischief makers than malicious criminals - realise that the Net is not some glorified computer game and the e-companies realise the absolute priority of security, the sooner e-business stands a real chance of turning a collective profit.