According to the press release Anonymous posted on Pastebin, the catalyst for this operation was finding a section with links to these type of sites on The Hidden Wiki, a site located on a .onion domain and part of a TOR-based darknet, and thus effectively hidden from view of everyone who doesn't use TOR or one of its gateways.
The group immediately removed the links, but they were restored a mere five minutes later by one of the site's admins. Subsequent analysis reveled to them that the overwhelming majority of those linked sites shared a digital fingerprint with the a hosting server of an ISP named "Freedom Hosting."
Armed with this knowledge, they contacted the ISP and demanded a takedown of over 40 child pornography websites, among whose is Lolita City which, according to the group, is one of the largest child pornography websites discovered to date containing more than 100GB of child pornography.
Freedom Hosting declined to comply, which spurred Anonymous to break into the hosting server and shut it down, but not before exfiltrating account details of 1,589 of Lolita City's users from the site's database - information that they subsequently made public.
For a while, the ISP managed to gain control over the server, restore the content form backups and improve its security posture, but Anonymous has allegedly managed to gain access once more and shut it down again.
"The owners and operators at Freedom Hosting are openly supporting child pornography and enabling pedophiles to view innocent children, fueling their issues and putting children at risk of abduction, molestation, rape, and death," Anonymous wrote. "For this, Freedom Hosting has been declared #OpDarknet Enemy Number One. We will continue to not only crash Freedom Hosting's server, but any other server we find to contain, promote, or support child pornography."
And while many have cheered their actions this time, many other individuals have wondered about the effectiveness of Operation Darknet. They maintain that these and similar attacks will only serve to make the pedophiles lay low for a while and hide.
Instead, they say, they could have notified the authorities about the existence of these sites, which would allow them to set up investigations that would hopefully lead to actual arrests.