Police, social services and experts were taken by surprise by the huge scale of internet child porn revealed by a major inquiry, peers have heard.
People - not technology - were the problem, peers heard
Operation Ore was launched in May 2002 to investigate customers who had accessed images from a US-based site.
Jim Gamble of the Child Exploitation and Online Protection centre said: "Operation Ore was a wake-up call. We were not prepared for that in the UK."
So far 2,300 people have been found guilty of offences.
Mr Gamble told the Lords science and technology select committee that 132 children had been rescued from "real time abuse" during the operation.
Some cases are still outstanding, and the CEOP was "investigating hundreds of suspects who were trying to access sites" as part of its continuing role.
"The volumes were unlike anything we'd seen before in a single crime type," Mr Gamble said.
"It was complex and sometimes people were seduced by the complex nature of it because it was the internet and you see it as a labyrinth.
"Historically there had been a tendency to say that 'we can't do anything about it because it's the internet'."
However, he said the operation had involved "great work by the British police service dealing in a complex area...with an old crime committed in a new environment".
The principle lesson learned from the operation was that the internet was "simply another a public place".
"The internet is not good or bad, the people who occupy it at any given time will decide how good or bad it is," Mr Gamble said.
'Threat of ignorance'
He said it was not the technology that was the problem, but the people who created the images and victimised the children.
Mr Gamble said: "The threat that will emerge is one of ignorance and perhaps arrogance on behalf the police service or others in places of responsibility where we assume we have done enough and we assume children know enough.
"I believe the best way of dealing with the new threat is through education, listening to young people and helping them identify the risks."
He asked peers to make child protection a priority in the national policing plan, to have internet safety as a curriculum requirement and to encourage the use of technology to block sites.