A Guardian investigation finds that Crunchy Moms, a Facebook group of more than 490,000 members that Meta's AI summarizes and its algorithms recommend into users' feeds, is a hotbed of false medical claims — that vaccines cause autism, that measles is harmless, that black salve cures cancer — despite Meta's own policies barring such posts. The Guardian reported 56 items there with no response, and experts warn children could be hurt as parents turn away from medicine.