"Do you have pizza delivery men in Britain?" asked Bruce Schneider of Counterpane Internet Security, which is based in San Jose, in the heart of Silicon Valley outside San Francisco.
"What has happened to Yahoo! is as if someone who didn't like you ordered 100 pizzas to be delivered to your house all at the same time. How do you defend yourself against that?"
Mr Schneider, whose company is working on a new security mechanism and liaising with other computer security companies, said that internet firms were now realising that they are almost powerless to resist a coordinated attack. Mr Schneider said that one of the greatest problems was that the hackers were not disrupting the internet companies for gain.
"It's not being done for profit," said Mr Schneider, who is one of a growing number of people entering the security side of the internet world in response to the near panic caused by the disruption. "Nobody's making any money." He said tracing malicious hackers was similar to pursuing hit-and-run criminals as opposed to kidnappers, as there appeared to be no clear motive.
"You've got to step back," he said. "If this is being done from eastern Europe there is no way to track them down. If it's being done in the United States then there is a possibility."
The task is vast, he said. Security and forensic experts visit the company that has been targeted and attempt to trace back the audit logs to see where the attack originated.
Like the companies they service, the security firm's day starts at 8am and can often finish late into the night. It is a badge of honour for many young internet companies to work "24-sevens" (24 hours a day, seven days a week) - which merely adds to the complications in assisting with security. This is painstaking work and requires the co-operation of small internet companies in a field that has still not worked out how to police or protect itself.
"This is malicious vandalism rather than mischief," said Mr Schneider, whose company was founded four years ago as it became clear that computer security was not being taken seriously by many start-up companies in Silicon Valley. "At the moment no one knows how to defend against it. Blackmail is a possibility - but I would hope that doesn't happen."
He said that there was no immediate solution in sight. One of the great strengths of the internet, its accessibility, is also turning out to be one of its great weaknesses. "There have been conferences on these attacks and we are trying to share knowledge," said Mr Schneider. But he acknowledged that there was no speedy solution in sight. "It's like curing malaria," he said. "You've got to drain the swamps."
