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. “It’s become a sounding board where people share ideas, and where these kinds of ideologies are amplified and expanded on, and ultimately, people are radicalized as a result.”
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.
The site remains nearly completely unmoderated, and its commitment to keeping up even the most violent speech has made it a venue for extremists to test out ideas, share violent literature and cheer on the perpetrators of mass killings. Users on 8chan frequently lionize mass gunmen using jokey internet vernacular, referring to their body counts as “high scores” and creating memes praising the killers.
Mr. Brennan, who has a condition known as brittle-bone disease and uses a wheelchair, has tried to distance himself from 8chan and its current owners. In a March interview with The Wall Street Journal, he expressed his regrets over his role in the site’s creation, and warned that the violent culture that had taken root on 8chan’s boards could lead to more mass shootings.
After the El Paso shooting, he seemed resigned to the fact that it had.
“Another 8chan shooting?” he tweeted on Saturday. “Am I ever going to be able to move on with my life?”
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.”