The Anonymous hacking group has posted a list of 1,500 people who it says used a child porn website.
The move comes after the group managed to take down more than 40 pedophile websites last week which were swapping images through the Tor anonymization network.
It all started when Anonymous came across a site hosted on a Tor darknet a couple of weeks ago that linked to images of child sex abuse.
The group warned the site to remove the links, but shut down services when it was ignored.
"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," says Anonymous in a statement on Pastebin.
"By taking down Freedom Hosting, we are eliminating 40+ child pornography websites, among these is Lolita City, one of the largest child pornography websites to date containing more than 100GB of child pornography.
"We will continue to not only crash Freedom Hosting's server, but any other server we find to contain, promote, or support child pornography."
It's published a list of over 1,500 individuals it says were users of the site.
"If the FBI, Interpol, or other law enforcement agency should happen to come across this list, please use it to investigate and bring justice to the people listed here," it says.
However, when similar vigilante activities have been carried out in the past, law enforcement agencies have been less than happy, saying it could jeopardize proper investigation.