Widespread distrust of our public health system is reviving long-debunked ideas on HIV and AIDS—and energizing a broad movement that questions the foundations of disease prevention.

Several million people were listening in February when Joe Rogan falsely declared that “party drugs” were an “important factor in AIDS.” His guest on The Joe Rogan Experience, the former evolutionary biology professor turned contrarian podcaster Bret Weinstein, agreed with him: The “evidence” that AIDS is not caused by HIV is, he said, “surprisingly compelling.”

The company’s AI algorithms gave it an insatiable habit for lies and hate speech. Now the man who built them can't fix the problem.

During the show, Rogan also asserted that AZT, the earliest drug used in the treatment of AIDS, killed people “quicker” than the disease itself—another claim that’s been widely repeated even though it is just as untrue.

Speaking to the biggest podcast audience in the world, the two men were promoting dangerous and false ideas—ideas that were in fact debunked and thoroughly disproved decades ago.