You're right: Firefox is showing you these even though you didn't visit them. Sadly, many of these "recommendations" are from politically charged sites. Vox is

You're right: Firefox is showing you these even though you didn't visit them. Sadly, many of these "recommendations" are from politically charged sites. Vox is notoriously far-left, Buzzfeed is leftist and often features sensational, click-bait headlines. Disappointed these are showing up on my Firefox homepage.