The company says these changes have decreased by more than 70 percent the number of views that borderline content gets from recommendations, although that figure cannot be independently verified. YouTube also says that among a set of pro-QAnon channels, the number of views coming from recommendations dropped more than 80 percent after the 2019 policy change.
Social media platforms have been under scrutiny for their policy decisions in recent weeks, as Democrats accuse them of doing too little to stop the spread of right-wing misinformation, and Republicans, including Mr. Trump, paint them as censorious menaces to free speech.
YouTube, which is owned by Google, has thus far stayed mostly out of the political fray despite the platform’s enormous popularity — users watch more than a billion hours of YouTube videos every day — and the surfeit of misinformation and conspiracy theories on the service. Its chief executive, Susan Wojcicki, has not been personally attacked by Mr. Trump or had to testify to Congress, unlike Jack Dorsey of Twitter and Mark Zuckerberg of Facebook.
Vanita Gupta, the chief executive of the Leadership Conference on Civil and Human Rights, a coalition of civil rights groups, praised YouTube’s move to crack down on QAnon content.
“We commend YouTube for banning this harmful and hateful content that targets people with conspiracy theories used to justify violence offline, particularly through efforts like QAnon,” Ms. Gupta said. “This online content can result in real-world violence, and fosters hate that harms entire communities.”
Mr. Rothschild, the QAnon researcher, predicted that QAnon believers who were kicked off YouTube would find ways to distribute their videos through smaller platforms. He also cautioned that the movement’s followers were known for trying to evade platform bans, and that YouTube would have to remain vigilant to keep them from restarting their channels and trying again.
“YouTube banning Q videos and suspending Q promoters is a good step,” he said, “but it won’t be the end of Q. Nothing has been so far.”