International police led by a UK team say they shut down the largest internet paedophile ring yet discovered.
The global forum had 70,000 followers at its height, leading to 4,000 intelligence reports being sent to police across 30 countries.
The operation has so far identified 670 suspects and 230 abused children.
Detectives say 184 people have been arrested - 121 of them were in the UK. Some 60 children have been protected in the UK.
The three-year investigation, Operation Rescue, was led by investigators from the UK's Child Exploitation and Online Protection Centre (Ceop).
Speaking at a news conference at The Hague in the Netherlands, investigators said the network hid behind a legal online forum which operated out of the country - but its members came from around the world.
Along with the Netherlands and the UK, suspects have been identified in Australia, Italy, Canada, New Zealand and Thailand.
The members of the network went into a private channel, boylover.net, and then used its secret systems to share films and images of abused children, said Rob Wainwright, director of European police agency Europol.
However, child abuse investigators, including a team from Ceop, had already infiltrated the network and were posing as paedophiles to gather intelligence.
In the UK, the 240 suspects include police officers, teachers and a karate teacher. One of the suspects in the UK is a woman.
The latest arrest was in Northamptonshire.
To date, 33 have been convicted, including John McMurdo, a scout leader from Plymouth. Another forum user was Stephen Palmer, 54, of Birkenhead, who shared abuse images with contacts in the US. A third man, 46-year-old Colin Hoey Brown of Bromsgrove, was jailed for making and distributing almost 1,000 images.
'New ground broken'
Peter Davies, head of Ceop, said: "The scale and success of Operation Rescue has broken new ground.
"Not only is it one of the largest operations of its kind to date - and the biggest operation we have led - it also demonstrates the impact of international law enforcement agencies working together with one single objective, to safeguard children and bring offenders to justice.
"While these offenders felt anonymous in some way because they were using the internet to communicate, the technology was actually being used against them.
"Everything they did online, everyone they talked to or anything they shared could and was tracked by following the digital footprint."
Operation Rescue began when Ceop and colleagues in the Australian Federal Police separately identified the site as a key online meeting place for abusers.
The two forces deployed officers to infiltrate the site and to identify the members who were posing the most risk to children.
One of the early breakthroughs in the investigation was the arrest of four suspects in Thailand in 2008. Two of the men were British.
In March of the same year, Ceop identified the owner of the site and the location of its server in the Netherlands. The owner of the server is now co-operating with Dutch police.
Rob Wainwright of Europol said the man running the server had used "advanced security techniques" which took months to break down.
"If you think you can use the internet to abuse children you are wrong," he said.
"We will not allow these offenders to carry on committing these awful crimes against young children. We will not rest until we have identified every offender that has been active in this network and others that might be operating on the internet."