Since GamerGate, 8chan has become a catchall website for internet-based communities whose behavior gets them evicted from more mainstream sites.
It hosts one of the largest gatherings of supporters of QAnon, who claim that there is an international bureaucracy plotting against the Trump administration.
And it has been an online home for “incels,” men who lament being “involuntarily celibate,” and other fringe movements.
“8chan is almost like a bulletin board where the worst offenders go to share their terrible ideas,” said Jonathan Greenblatt, the chief executive of the Anti-Defamation League.
8chan has been run out of the Philippines by Jim Watkins, a United States Army veteran, since 2015, when Mr. Brennan gave up control of the site.
Mr. Watkins, who runs 8chan along with his son, Ronald, has remained defiant in the face of criticism, and has resisted calls to moderate or shut down the site.
On Sunday, a banner at the top of 8chan’s home page read, “Welcome to 8chan, the Darkest Reaches of the Internet. »