The platform "Boystown" was active since at least June 2019 and had a membership of over 400,000. It was only accessible via the so-called darknet.
https://www.dw.com/en/german-police-shut-down-major-darknet-child-sex-abuse-platform/a-57408253
Four German citizens between the ages of 40 and 64 were detained in relation to the case, three on suspicion of working as administrators for the platform — one of whom was arrested in Paraguay. Another man was taken in under suspicion of being a registered member and the platform's most active user, having contributed more than 3,500 posts.