On YouTube, an ad for the car company Mazda appeared before a video that repeated the racist falsehood that Haitian migrants in Ohio were “eating ducks on the side of the road.” An ad for the software giant Adobe showed up alongside another video that claimed “people have had their pets abducted and eaten by people who shouldn’t be in this country.” Even an ad for Vice President Kamala Harris was placed ahead of a video that spread the unsupported statement that migrants were “going to parks, grabbing ducks, cutting their heads off and eating them.” Many advertisers have tried for years to avoid sharing space with content about polarizing politics, hate speech or misinformation.