Hacking is almost an occupational hazard for internet companies - though most attacks will not be on the same level as those undertaken recently on some big-name sites.

A huge blitz of information shut down Yahoo! for three hours. Amazon and eBay were also hit.

In the UK, the industry is developing a greater awareness of the problems with security.

"There are different cultural approaches to security. We don't have the tidal wave of users yet that they do in the US, but it will come," says Colin Bastable, sales director with security specialists nCipher.

He stresses the difference between the "denial of service" attack on Yahoo! and proper hacking, but says security cannot be underestimated.

"I think a lot of companies don't realise the scale of the issue. There are so many ways into a company, even through an outside fax server."

Mr Bastable says it is important that security measures do not slow down transactions, or customers will not visit the site.

Firms should check their ISP's credentials, and try to prevent "social hacking" - staff letting slip information.

"The biggest weakness in a security policy is people," he says. "Simple things like not making your password too obvious can be important."

There are physical steps that can be taken as well.

XTML has just opened what it claims is Europe's most secure server hosting facility.

It is in a former gold bullion bank vault in Manchester, and servers can be stored in bombproof surroundings that are also shielded against electro-magnetic impulses.

Insuring against risk

Coupled with the facility is the company's e-commerce insurance policy, which protects against business interruption, viruses and hacking.

Rob Goldhawk specialises in cyber liability for Hiscox Insurance. He says having protection is vital for businesses.

"The costs depend on what you are doing and how high-profile your site is," he told the BBC.

"If you know there are going to be credit card numbers held on certain sites and held on certain servers then obviously hackers are going to go after them.

"The problem is that you want to be able to carry on trading on the internet, and there are certain things you have to do to make sure you can carry on.

"I think you should undertake some physical security and also buy insurance to back it up," Mr Goldhawk advises.

He acknowledges that UK insurance companies have been slow to meet the internet industry's demands, but believes they can evolve and change.

Opportunities to be had

While individual companies might be shocked into checking their security following the recent spate of attacks, there are also much wider effects.

The stock markets were unnerved, and the attacks contributed to the eighth largest point decline seen on the Dow Jones industrial average, which fell 258.44 points, or 2.36%, to 10,699.16.

The technology-heavy Nasdaq index, which had been reaching record levels, was down 1.45%.

But there was good news for some businesses, especially those dealing in anti-virus software.

Trend Micro jumped 7.75% on the Toyko stock exchange, while Vertex Link's shares increased by 12.5%.

Nissin Electric, which distributes firewall software to protect internal networks, was up 19.25%.

As in most crises, there are clearly business opportunities to be had.