Messages on another website, which TechCrunch has seen, were happy about the hack. One person said the hacker had been inside 4chan's system for over a year.

Some pictures online showed what looked like the system used by the website 4chan. These pictures apparently showed the site's system, its main code, and tools for stopping users from accessing the site. Only the people who manage the site should be able to see this. The leaked information also included a list of people who are said to manage 4chan, as well as "janitors." Janitors are users who can remove messages, but they don't have as much power as managers. Managers, for example, can also see the internet addresses of users.

Since 4chan is known for its connections to political violence, this cyber attack might reveal the people who manage these online forums, which are now very important for alt-right groups.

TechCrunch got in touch with some people whose email addresses were shared and talked to one of them. A 4chan worker, who didn't want to be named, told TechCrunch they are sure the shared information and pictures are true.

"I have no reason to think differently," the cleaner said.

I'm quite surprised. 4chan's moderators have had leaks before, but this problem is clearly much bigger," the moderator told TechCrunch. "I'm not happy about this. I'm sure most other people aren't either. But many of us have worked here for a long time. Sharing people's private information is a common activity on 4chan, and we always knew we might be at risk of being found out.

"I've been very worried about the leaked information, for clear reasons," the janitor said. "I think a hacker or hackers taking control of 4chan is probably 'worse' than just screenshots, especially for the website to keep working."

The janitor also said that it seems the hacker got the personal information of people who pay for a 4chan Pass. These people pay the website to post more and use a special VIP area.

4chan did not reply to an email asking for a comment.

4chan is an online forum where people can post without using their real names. Some people think of it as a negative place on the internet. Often, it's a place for sharing images, and users post things that are meant to shock others. Sometimes, things that start on 4chan show up in the real world as simple memes or as angry messages.

Memes like Pepe the Frog and rage comics started on 4chan and are now everywhere online. But 4chan is most famous for its political sections, where extreme right-wing ideas can make young users believe in white supremacy. QAnon, a group of right-wing people who support Donald Trump and believe in conspiracy theories, also started on 4chan.

The man who killed 51 people at two mosques in New Zealand in 2019 used the website 4chan a lot since he was a teenager. In 2022, an 18-year-old man killed 10 Black people in a shop in New York. His long written statement included ideas from the New Zealand killer's online messages.