Measles Outbreak Sparks Vaccine Debate in Facebook Group
Back in August, when a measles outbreak hit Lancaster County, Pennsylvania, a mother sought guidance in a large public Facebook group called Crunchy Moms regarding whether she should immunize her three-year-old toddler. One member responded that children cannot die of measles and called it literally impossible, while another advised the parent not to administer the shot, according to an investigation by The Guardian.
None of those claims are true.
At the end of the user’s post, Meta’s AI system summarized the 589 responses by noting that commenters claimed the vaccine was unnecessary or harmful. One scientist who monitors the platform calls Crunchy Moms “the most dangerous group on Facebook”, and doctors, researchers, former employees and public health advocates told The Guardian that the findings show the pendulum at Meta has swung back to a time when there was little moderation of false health information.
Meta Eliminates Fact Checkers Before Inauguration
Meta eliminated fact-checkers in the United States and dialed down active moderation shortly before the inauguration of Donald Trump, following remarks by billionaire founder Mark Zuckerberg that there was too much censorship on the platform. The company still maintains a policy prohibiting harmful health misinformation, but it is not known how Meta enforces it.
The Guardian found that dangerous medical misinformation circulates freely within Crunchy Moms, a group boasting more than 490,000 members. The platform promoted the group into users' feeds even when they did not seek it out.
Sara Rupe launched Crunchy Moms in March 2025, less than three months after Zuckerberg announced Meta’s new hands-off approach. Rupe said the group does not give her any alerts about what some might call medical misinformation.
Facebook Ignores Reports of Medical Misinformation
During testing, a journalist reported more than 50 posts and comments from Crunchy Moms to Facebook for violating Meta’s own standards regarding vaccines and medical advice, but the platform took no action and did not respond to the reports. Meta stated that its policies permit personal experiences and scientific research, removing misinformation only when it is likely to directly contribute to the risk of imminent physical harm.
Renée DiResta, a professor at Georgetown University who studies online manipulation, noted that Meta’s current approach mirrors policies from a decade ago that allowed anti-vaccine sentiment to spread unchecked. Researchers estimated that exposure to vaccine-skeptical content on the platform during the pandemic reduced people’s intention to get vaccinated.
Meta did not respond to detailed inquiries regarding Crunchy Moms or expert assessments that health misinformation is commonplace within the group.
Frequently Asked Questions About Facebook Health Misinformation
How many members belong to the Crunchy Moms group?
The public Facebook group has grown to more than 490,000 members since its creation in March 2025.
What did research estimate regarding vaccine-skeptical content on social media?
Researchers estimated that exposure to vaccine-skeptical content during the Covid-19 pandemic reduced vaccination intentions, resulting in millions fewer Americans getting vaccinated.
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