Police arrested the suspects in the operation, dubbed "Deep Connection," which also lead to the identification of dozens of victims.
The administrators of the site hid behind the secrecy of the dark web, a part of the public Internet where users are hidden behind layers of servers designed to anonymize web traffic.
It was only after the 2014 arrest of an Australian member of the community, Shannon McCoole, that authorities were able to launch an investigation into the network by posing online as McCoole.
McCoole, a childcare worker, was sentenced in 2015 to 35 years in prison for child pornography and abusing minors as young as 18 months old. Investigators found him with 53,000 digital child abuse images.
The child pornography ring connected to Tuesday's arrests spanned five continents and had roughly 45,000 members, Italian police said. The community hosted roughly 400,000 links to child abuse material.
The organization of the online network was sophisticated and hierarchical. Members were forced to upload monthly quotas of child pornography and could be suspended or blocked if they failed to meet these minimums. The group established an incentive system that rewarded prolific contributors with opportunities to sexually abuse children in real life, police said.
Italian police were assisted by the United States Federal Bureau of Investigation (FBI) and police from the Australian state of Queensland.
