An attack on the Dark Web left a whopping 20 percent of it in shambles. On Friday, a vigilante managed to hack into Dark Web hosting service, Freedom Hosting II, after realizing that it was allowing child pornography sites. As first reported by the Verge, visitors to more than 10,000 sites on Friday saw not their expected content, but rather a message that read, “Hello, Freedom Hosting II, you have been hacked.”

According to the hacker, Freedom Hosting II must have been aware that it was managing child porn sites — those in question required gigabytes of data despite the fact that the hosting service officially claims to allow no more than 256MB. As part of the hack, not only was the usual content replaced with the hacker’s message, but it also served up a data dump (without user info), and an explanation as to the reason for the hack.

This is by no means the first time Freedom Hosting has come under fire for child pornography. Back in 2013, law enforcement officials busted the service, ultimately allowing for several child pornography prosecutions. But just a few years later, it looks like the second iteration of the host is running into the same issues.

On Saturday, the hacker spoke to Motherboard about the rationale behind the attack. “This is in fact my first hack ever,” the intruder wrote via an email sent from the same address posted to the hacked Freedom Hosting II sites. “I just had the right idea.”The hacker continued, “Initially I didn’t want to take down FH2, just look through it,” but after finding no fewer than 10 child pornography sites with some 30 GB of files, action had to be taken.

Thus far, it looks as though the hacker had benevolent intentions, and is handling the data in a responsible manner. Apparently, the information will be sent to a security researcher who will ultimately relay data to law enforcement, who could use it to bring the child pornographers to justice. However, the FBI may not be fully pleased with this vigilante action. As Motherboard explains, “In recent years, when law enforcement agencies such as the FBI have taken over dark web sites or hosting providers, they have then tried to identify individual users by deploying malware. But now with the plethora of Freedom Hosting II child pornography sites shut down, the feds might not be able to use that sort of tactic at all.”