Francis Maude, a British official in charge of cybersecurity in the government, said the Internet holds up a mirror to society, reflecting both the best and worst elements.
"There is a dark side to the Internet," he said in his address. "We need to protect the Internet from hostile actors -- the criminals, the hackers, the terrorists -- who want to exploit it for less positive ends."
He said cybersecurity depends on a "multi-stakeholder approach" that doesn't rely too much on state intervention, which he said would stifle the free exchange of ideas on the Internet.
At the same time, the British Serious Organized Crime Agency acknowledged that its Web site was targeted by a Distributed Denial of Service attack and forced offline.
A spokesman for SOCA told the BBC the attack didn't pose a security risk to visitors.
"SOCA's Web site contains only publicly available information and does not provide access to operational material," he said.
SOCA in April teamed up with U.S. law enforcement officials to investigate Web sites linked to the sale of stolen financial information.