@Defiance @kevinrns @Flipboard Yes. We ensure this through a tremendous amount of human and algorithmic moderation that, while not perfect, has scaled nicely over the past 14 years as we've built Flipboard. WRT publications, we manually screen domains before they are able to be recommended algorithmically. We also explicitly disallow domains that we have identified as having hate speech, nazis, racism, transphobia etc. As they say in computer science, "Garbage in, garbage out" so we actively work to proactively prevent toxic domains from ever entering our algorithms rather than trying to reactively deal with individual posts all the time which is a losing battle.
It's not a perfect system so we also rely on user reporting and take action without equivocation when appropriate.