Children's Health Defense, led by Robert F. Kennedy Jr., is one of the largest anti-vaccine groups in the United States.

Children's Health Defense said in an email that the social networks took down its accounts after a 30 day ban. Mr. Kennedy runs a nonprofit that accused the apps of being censorship.

The group said that removing CHD accounts was evidence of a clearly orchestrated attempt to stop the impact.

Mr. Kennedy said that Facebook was being used by the federal government to silence criticism of government policies.

Children's Health Defense is seen as a sign of vaccine resistance. According to the Center for Countering Digital Hate, the organization was one of the top 12 misinformation spreaders on the internet.

The main accounts of Children's Health Defense were removed by Meta because they had violated the company's policies on medical misinformation during the coronaviruses epidemic. According to Children's Health Defense, it had more than half a million followers on its main social media accounts.

Mr. Kennedy is the son of the former senator and U.S. attorney general. He is still able to speak online even though his account has been removed. Mr. Kennedy's personal Facebook page has more than 247,000 followers and is still up even though he was banned from social media.

According to a review by The New York Times, the California, Florida, and Arizona chapters of Children's Health Defense still have thousands of followers on Facebook.

Children's Health Defense has lied about the safety of Covid-19 vaccines, saying they cause organ damage and harm pregnant women. The organization tried to sow doubt about other vaccine types. In the last two months, it claimed that vaccines for tetanus caused infertility and that there was a rise in the number of cases of the disease in the world.

Meta has policies that forbid medical misinformation, but they have trouble with how to enforce them. Two people with knowledge of the conversations, who asked to remain anonymous because they were not authorized to speak publicly, said that the company has had discussions about removing the accounts of Children's Health Defense from social media.

Meta's president of global affairs wrote an open letter about the company's policies. As many parts of the world return to normal, the policies about Covid-19 misinformation may need to be reconsidered.

Meta only removed posts that posed a risk of imminent physical harm before the Pandemic. False claims about the transmissibility of the virus were removed during the Pandemic. He suggested that the measures may no longer be necessary.

He said that 25 million pieces of Covid-19 misinformation had been removed.

Misinformation experts say that conspiracy theories about Covid-19 are still popular on social media.