As the number of new coronavirus cases surges across the country and mitigation strategies such as wearing masks are recommended or required in some areas for public health, Facebook groups with thousands of members are dedicated to promoting harmful misinformation about wearing masks.

The Centers for Disease Control and Prevention (CDC) recommends that “people wear cloth face coverings in public settings” and while interacting with people not living in the same household -- especially in instances where social distance is difficult to maintain -- to reduce coronavirus transmission via respiratory droplets. That recommendation is based on what is currently known about the virus and emerging evidence of the effectiveness of these coverings in reducing the spread. Public health experts agree with the CDC recommendation.

As the spread of misinformation online continues to hamstring efforts to contain the coronavirus pandemic, Facebook claimed it would “remove COVID-19 related misinformation that could contribute to imminent physical harm.” Facebook has previously removed videos that falsely suggest that wearing a mask can make people sick, acknowledging that such claims violate its policies -- but only after the misleading videos had already received millions of engagements on the platform. Facebook has struggled to contain the spread of coronavirus misinformation, particularly videos, and the platform remains a hotbed for coronavirus misinformation, from viral anti-mask Facebook posts to scammers promoting bogus coronavirus cures.

Media Matters found at least 55 Facebook groups dedicated to opposing the use of masks to reduce the spread of COVID-19. These groups have a total of over 57,000 members, with more than 10 groups that have over 1,000 members and one group with over 20,000 members. Although some groups were created as far back as April, the majority of them have been created since June 17, with eight such groups created in the first week of July. One Georgia-based anti-mask group, which was created on July 3, already has over 600 members.

With more Facebook groups against masks being created and membership in these groups growing, misinformation about masks can quickly spread on the social media platform. And as nearly 70% of the groups identified by Media Matters are private, it will likely be more difficult for Facebook to review harmful content. For example, one viral post filled with misinformation about masks has been posted in at least seven Facebook groups.

Media Matters reviewed posts in some of the Facebook groups and found that many of these groups are filled with harmful medical misinformation about masks. In addition to this harmful misinformation, there are also members sharing conspiracy theories about masks being a form of government control, repeating misinformation from President Donald Trump, promoting in-person rallies, encouraging others not to wear masks, and organizing lawsuits against mask mandates.

Here are some examples of harmful misinformation about masks from 10 anti-mask Facebook groups, each with over 1,000 members:

Bare Face is Legal (private group with over 20,000 members)

• On July 1, a member of the group shared a meme claiming that “forcing people to wear masks has nothing to do with safety” and calling it “an experiment to see who’s a follower and who isn’t.”

• In a post from July 7, a member suggested that wearing masks could cause the “death of children.”

• In another post on July 7, a member asked for “studies on why the mask is unnecessary.” Other members shared links to anti-vaccine websites and an op-ed written in Townhall by Ted Noel, who has previously fueled right-wing conspiracy theories.

Million Unmasked March (private group with over 6,800 members)

• On June 30, a member shared a video from Del Bigtree, who is a leading figure in the anti-vaccine movement. In the video, which has earned nearly 30,000 interactions (reactions, comments, shares) on Facebook, Bigtree claimed to perform a test that proves masks are “toxic for children.”

• In a post on June 29, a member said that the media knows masks are “ineffective” and claimed, without evidence, that the “reality of the masks” includes “deprivation of oxygen and the inhalation of CO2... and the psychologically damaging aspects of this,” and will even “exacerbate” seasonal illnesses in children. The member went on to write they are “starting to wonder if the actual plan is to sicken our children so they can sicken us and drive us to get a vaccination.”

• On July 3, a member posted a meme that inaccurately claimed, “There is no scientific evidence that wearing a cloth mask will reduce the spread of COVID-19.”

Call to action against Washington mask requirements (private group with over 6,000 members)

• On July 7, a member posted a link to commentary from Denis Rancourt, a controversial former physics professor. In the commentary, which has not been published in a scientific journal, Rancourt said that “masks and respirators do not prevent transmission of viruses” and claimed that it “illustrates the degree to which governments, the mainstream media, and institutional propagandists can decide to operate in a science vacuum, or select only incomplete science that serves their interests.”

• In response to a post on July 6 questioning the efficacy of masks, several group members claimed that masks are “useless,” saying that “healthy people shouldn’t wear masks,” and called people wearing masks “sheeple.”

• On June 19, one member shared a website claiming “MASKS DON’T WORK” and promoted debunked misinformation that masks can lead to “carbon dioxide toxicity.”

Unmasked CT (private group with over 3,000 members)

• In response to a member of the group asking for links showing masks are harmful that they can send to their child’s school speech therapist, other group members provided commentary and sent videos from discredited figures in the anti-vaccine movement.

• In response to a post on July 6 criticizing people who wear masks, one member claimed that “this entire virus is nonsense” but said even if it was true that asymptomatic people can spread COVID-19, not wearing masks “helps towards [herd] immunity.” Another member made the unsubstantiated claim that “83% of people who LIVED with a covid patient were NOT infected.” 

• On July 7, one member posted a video of a physician in Texas who claimed to have anecdotal evidence of success treating COVID-19 with hydroxychloroquine, which has not been proven to be an effective treatment, and said that wearing masks “prevents us from developing passive immunity, so if you’re out in the public and you contract some disease and you develop antibodies to this, you could passively, potentially give your antibodies to someone else and their own immune system might develop immunity to the same disease.” The video posted in Unmasked CT appears to have been removed by Facebook, but had already been viewed over 850,000 times.

Ohioans Against Mandatory Masks (private group with over 1,900 members)

• In a post on July 7, a member called masks a “pseudo-medical device” and made unsubstantiated claims that they are ineffective and prevent people’s “ability to breathe oxygen unobstructed.”

• In response to a member asking for an article about “how masks are dangerous to health” on July 5, other group members posted a link to Rancourt’s commentary and a flyer that said masks decrease oxygen intake, increase toxin inhalation, and shut down the immune system.

• On July 7, one member shared a video with Kelly Victory, a Colorado doctor who has been spreading conspiracy theories about the virus. In the video, which has more than 1 million views, Victory said, “There is no scientific justification for normal, healthy people to be wearing masks. In fact, prolonged mask wearing actually increases the risk of disease to the wearer.”

Mask Free PA (private group with over 1,600 members)

• In response to a post on July 5 from a group administrator, members made unsubstantiated claims about masks lowering oxygen levels, raising blood pressure, and causing excess carbon dioxide levels. One member also shared a video from an anti-vaccine figure claiming the “levels of carbon dioxide inside a mask” would “shock any parent.”

• On July 5, an administrator of the group posted a meme with a logo mimicking the Pennsylvania Department of Health, which said: “By making such a half-hearted effort, your mask only says you want people to THINK you care about others. Drop the pretense. Drop the mask.” Other members responded to the post with claims that masks are toxic for children and that doctors agree “masks do nothing outside of medical facilities.”

• In a post on July 7, a member of the group posted a meme listing reasons why they don’t wear a mask, which included “I like breathing oxygen,” “99.9% survival rate,” and “I don’t believe in hoaxes.”

Keep Florida Open and End Mandatory Mask Wearing (public group with over 1,600 members)

• On June 18, one member posted a graphic pushing misinformation about the impact and effectiveness of people wearing a mask.

• A July 7 post displayed a warning on a box of masks in order to discredit the use of masks more broadly.

• Another post from July 2 shared a meme arguing that Muslims who have “worn face coverings their entire life” are “still reported to have COVID-19” as evidence that face masks don’t work.

No Mask High Five Challenge (public group with over 1,100 members)

• On July 7, a member posted a graphic detailing the “science” against wearing masks with the caption “Face masks are pure BS.”

• A July 6 post featured a link to a YouTube video by Rashid Buttar titled “What face masks actually do to your health,” which was labeled “false information” by independent fact-checkers (YouTube has previously removed Buttar’s videos for pushing coronavirus misinformation).

• On June 25, a member shared a “face mask exempt card” that was also labeled “false information” by independent fact-checkers.

Mohave County AZ Against Mandatory Face Masks (public group with over 1,100 members)

• On July 5, one member posted a graphic arguing that if masks really worked, businesses shouldn’t need to be closed.

• Another July 4 post argued that masks are “a mind control device.”

• On July 7, one user posted a graphic detailing supposed “facts” about “face mask safety,” including claims that wearing a mask could shut down your immune system or increase risk of contracting the virus.

ANTI-MASK 2020 (private group with over 1,000 members)

• On July 7, one member shared an article about mitigation of flu transmission as justification to claim that masks are ineffective against coronavirus transmission. In response to the flawed argument, another member claimed that Chinese people had contracted coronavirus even though they “wear masks even without a pandemic.”

• In a post on July 6, a member posted a meme, which has also been shared in other anti-mask Facebook groups, that listed supposed reasons why they don’t wear a mask.

• On July 7, a group moderator shared a video of anti-vaccine figure Michael Gaeta, who claims to provide “wholistic health education,” including a course “dispelling vaccine myths.” In the video, Gaeta said, “What’s become super clear is that there is no scientific evidence to support the use of the masks. It is based on assumptions, and it’s based on basically propaganda, is what it amounts to, and we’re making this sweeping public health requirement for massive parts of the country and the world without any actual basis in science, evidence, or data.”