Social media companies are increasing their vigilance about removing coronavirus conspiracies. Facebook, in particular, continues to update its policies as the outbreak — and corresponding disinformation — spreads.

On Tuesday, Mark Zuckerberg reiterated in a Facebook post that the platform was removing conspiracy theories related to the coronavirus that have been flagged by global health organizations, in addition to labeling coronavirus misinformation with “fact check” labels to let users know that such content had been rated false. Zuckerberg also said that Facebook is providing the World Health Organization (WHO) “as many free ads as they need.” At the same time, Zuckerberg said the company will block ads that try to exploit the situation, such as those that claim a product has a miracle cure for the Covid-19 disease.

It’s been more than two months since a novel strain of coronavirus popped up in Wuhan, China, and proceeded to spread to countries across the world. And as that’s happened, panic has continued to disseminate throughout social media, forcing tech platforms to grapple with what the World Health Organization is calling an “infodemic.”

As of March 4, the novel coronavirus linked to Wuhan, China, has infected nearly 95,000 people, mostly in mainland China, and there are cases popping up throughout the United States. More than 3,200 people have died, though researchers at Johns Hopkins tracking the disease also report more than 51,000 recoveries from the illness.

With more and more people searching online for information about the coronavirus outbreak, they can easily encounter a barrage of misleading and potentially dangerous information. And the WHO, which has also released its own “myth-busting” resources, is warning that misinformation about the novel coronavirus has caused harmful stigmatization and discrimination. In the US, for instance, there is a growing number of reports about misinformation fueling racism against Asian Americans.

Facebook, Twitter, YouTube, and TikTok have all told Recode that they’ve been working to promote factual content and some are limiting the reach of posts with misinformation on their platforms. Twitter, for instance, has put a warning label linking to the Centers for Disease Control and Prevention (CDC) when users search “coronavirus.” Meanwhile, the WHO has now joined TikTok in an effort to boost accurate information about the illness, and several of those companies met with the public health organization at Facebook back in February.

The CDC recommends several measures to help prevent the spread of Covid-19: Wash your hands often for at least 20 seconds.

Cover your cough or sneeze with a tissue, then throw it in the trash.

Clean and disinfect frequently touched objects.

Stay home as much as possible, and do not go out if you are sick.

Wear at least a cloth mask in certain public settings.

Contact a health worker if you have symptoms. Guidance may change. Stay informed, and stay safe, with Vox’s coronavirus coverage hub.

Still, efforts by these social media platforms have not managed to stop the spread of misleading or outright false hoaxes about the outbreak in the form of posts and videos that have racked up thousands of clicks, “Likes,” and shares. A significant amount of false information about the coronavirus is also spreading on private channels. Take WhatsApp, for instance. As the Washington Post reported, the encrypted platform has seen a flurry of wrong information about the coronavirus, creating panic among its users throughout the world.

Another problem involves politicians promoting the idea that the coronavirus is a hoax or spreading other conspiracy theories about the virus. A Facebook spokesperson confirmed to Recode that the company would remove false claims and conspiracy theories flagged by world health organizations that have been shared by politicians or elected officials.

While we’re seeing a wide variety of false coronavirus posts across these platforms, it’s still hard to say how widespread the misinformation problem is. But it’s significant enough that well-regarded institutions, including Johns Hopkins University, research centers in England, and even NASA have had to issue statements or comments debunking claims that have been floated online. Advocacy groups such as Media Matters have also been busy tracking down false and misleading posts.

Although there is a seemingly endless stream of sources spreading misinformation about the Wuhan coronavirus around the web, we’ve identified and debunked a few of the most pervasive hoaxes.

False: The novel coronavirus sickness is caused by 5G

On social media, some are pushing the idea that the novel coronavirus was caused by or can be linked to deployment of 5G technology in Wuhan, China. There are several “strains” of this theory floating around online. One premise is that 5G technology can weaken the immune system and make the common cold more virulent. Another promotes the idea that the 5G technology itself is causing the symptoms that have been attributed to the novel coronavirus. One version of the theory pushes the idea that the technology absorbs oxygen in the lungs, which “causes coronavirus.”

That idea has been flagged false by a UK-based third-party fact-checker, called Full Fact, that works with Facebook. There’s no evidence that 5G impacts the immune system, and no proof that it has any link to the novel coronavirus.

False: There’s a plot to “exterminate” people infected with the new coronavirus

On social media, some have floated the claim that China sought permission from the country’s Supreme Court to kill people infected with the novel coronavirus. Several fact-checkers, including Snopes, have determined these reports to be false and to have originated from a website with several “red flags.”

Poynter observed that some social media accounts continue to push the idea that China is planning to kill people with the illness. Meanwhile, some accounts have floated that the idea that the incineration of human bodies is causing an excess of sulfur dioxide, which they imply can be seen from satellite images. There is no evidence that any of this is true, and a research meteorologist from NASA told the UK fact-checking organization Full Fact that the images these theories are based on aren’t live satellite data.

“Although satellite data has been used in the construction of the emission inventories, these emissions do not account for the day-to-day variations in SO2 emissions and as such cannot account for sudden changes in human activity,” Arlindo M. da Silva told the fact-checking organization.

False: Scientists have proven that humans got the novel coronavirus from eating bats

One prominent theory is that the coronavirus spread through human consumption of bats. BuzzFeed reported that a prominent video about the novel coronavirus in Hindi that’s attracted more than 13 million amplified the claim that eating bats caused the coronavirus outbreak. This theory, which has popped up throughout social media, is also linked to unfounded speculation that the coronavirus was started at the Wuhan Virology Institute.

Those claims have helped fuel racism against people of Chinese descent, and Asian people more broadly, throughout the world.

It’s true that there has been research into a potential link between bats and the coronavirus, but it’s important to be very cautious in interpreting the findings. First, there is no evidence that eating bats caused the coronavirus outbreak. And Jonathan Epstein, a veterinarian and an epidemiologist EcoHealth Alliance, told Vox earlier this month that it’s “still not known” whether this outbreak started with bats at an animal market.

“It’s clear there was some environmental contamination in the market that includes this virus. And that’s what we know so far. So it’s likely that people were infected in that market,” Epstein told Vox. “But I think there is still some question about how the earlier cases may have been exposed.”

And here’s what the CDC reports: “Analysis of the genetic tree of this virus indicates it originated in bats, but whether the virus jumped directly from bats or whether there was an intermediary animal host is not, yet, known.”

False: Scientists predicted the virus will kill 65 million people

In October 2019, a Johns Hopkins research center ran an “exercise” that aimed to model the global response to a potential epidemic. Many people online have misinterpreted the study and erroneously linked its predictions to the possible death toll of an outbreak similar to what we’re currently witnessing with the novel coronavirus. In other words, the Johns Hopkins study had nothing to do with the coronavirus, although the scenario studied might seem similar.

This is a popular line of misinformation on Twitter. There are several tweets, including one that’s still up with over 140,000 “likes,” claiming that scientists have predicted that the Wuhan coronavirus will kill 65 million people. That’s not accurate.

“We modeled a fictional coronavirus pandemic, but we explicitly stated that it was not a prediction,” the Johns Hopkins Center for Health Security said in a statement. “We are not now predicting that the nCoV-2019 outbreak will kill 65 million people.”

False: China built a biological weapon that was leaked from a lab in Wuhan

Right now, it’s not clear where this new strain of coronavirus originated. Officials believe it may be linked to a seafood market in Wuhan, but scientists still aren’t exactly sure how or where it developed.

On social media, however, there are many other completely unproven theories about its origin that imply the outbreak of the virus may be linked to bioweapons research at the Wuhan Institute of Virology, a research institute that houses the Wuhan National Biosafety Laboratory. This Facebook post that’s been shared more than 4,000 times says that it’s “believed that the Wuhan Institute of Virology is where the disease may have originated.”

This idea appears to be based, in part, on comments a former Israeli military officer shared with the Washington Times, a right-wing outlet whose past articles have suggested that President Barack Obama might be Muslim and have spread conspiracy theories. Back in January Jim Banks, a Republican congressman from Indiana, even tweeted out a link to the Washington Times article. His tweet has been shared more than 1,000 times. (Rep. Banks did not respond to a request for comment.) And this month, Sen. Tom Cotton also amplified similar speculations.

As shocking as the biowarfare lab theory might be, experts have told the Washington Post that there’s no evidence to support it. And the lab itself said in a statement that misinformation had “caused severe damage to our researchers who have been dedicated to working on the front line, and seriously interrupted the emergency research we are doing during the epidemic.”

False: Chinese spies smuggled the virus out of Canada

Social media posts are pushing the unproven premise that the novel coronavirus found in Wuhan was smuggled from a lab in Canada as part of China’s clandestine quest for a bioweapon, a theory debunked by Politifact. It’s a theory that seems to be somewhat related to the Wuhan lab conspiracy. One tweet by Republican Party official Solomon Yue, who has more than 100,000 followers, said: “#coronavirus is stolen from Canada by espionage & sent to Wuhan to be weaponized to kill foreign enemies.”

#coronavirus is stolen from Canada by espionage & sent to Wuhan to be weaponized to kill foreign enemies. Now the deadly weaponized virus kills 80 Chinese & no foreigners & becomes Emperor Shithole's Chernobyl! https://t.co/aOyIbvmC39 — Solomon Yue (@SolomonYue) January 27, 2020

Although a Chinese researcher working in Canada is under investigation for a possible policy breach after she was invited to the Wuhan lab twice a year for two years, according to Politifact, there’s “no evidence” to support the claim that she “stole coronavirus samples and gave them to the Wuhan lab to create biological weapons.”

False: A coronavirus vaccine already exists

Another popular theory is that a vaccine for the novel coronavirus already exists, and some are even suggesting that the vaccine was previously patented. While researchers in several countries are working to develop a vaccine, no such vaccine has yet been developed, according to FactCheck.org and Politifact. But this hasn’t stopped people from going online and claiming otherwise.

A recent post on Facebook claims that the coronavirus was a “set up” to sell vaccines and includes screenshots claiming to show a patent for a new vaccine. In this particular case, because Facebook’s fact-checkers verified the post as containing false information, a handful of “related articles” show up below the post, pointing users to verified sites that debunk the vaccine conspiracy theory. If you try to share the post, Facebook issues a warning stating that independent fact-checkers have said it contains false information.

But even though Facebook has placed warnings on some vaccine hoaxes related to the Wuhan coronavirus, the content isn’t flagged as false on every platform. On Twitter, for example, one tweet that’s gained close to 2,000 “likes” suggests that a vaccine for the coronavirus is owned by the Pirbright Institute, an English infectious disease research institute that focuses on farm animals.

This claim is false. The Pirbright Institute issued a statement shared by FactCheck.org, clarifying that its researchers don’t work with human coronaviruses, and that a patent that they hold is unrelated to the current coronavirus linked to Wuhan.

Some have also attempted to profit from spreading the false information that’s there’s a cure (there’s none yet), and the Federal Trade Commission warned the public earlier this month that “scammers are taking advantage of fears” about the illness and “setting up websites to sell bogus products, and using fake emails, texts, and social media posts as a ruse to take your money and get your personal information.

False: There were 100,000 confirmed cases in January

As of March 4, there were nearly 95,000 cases of the coronavirus, but at the very end of January, when that number was less than 10,000, people were vastly inflating the number of infected people beyond what any official source has reported.

It’s an important reminder that, when trying to figure out the scale of the virus’s spread, it’s worth looking to reputable, official sources, such as the World Health Organization. The Center for Systems Science and Engineer at Johns Hopkins also maintains a useful map documenting the number of confirmed cases throughout the world.

It’s true that on January 26, one public health expert told the Guardian, however, “Almost certainly many tens of thousands of people are infected.” He added, “My best guess now is perhaps 100,000 cases right now.” But that big scary number can be misleading because it was a guess and that number had not been confirmed.

Nevertheless, many popular posts on social platforms spread statistics that served to scare people with numbers that do not match the official count. Some of these posts cite medical workers in Wuhan, without evidence. For instance, one YouTube video posted on January 25 shows someone identified as a nurse, who says there were as many as 90,000 people infected with the disease in China alone.

Similarly, in late January on Twitter, an account disguised as a news outlet shared an audio clip that claimed that the time, 100,000 people have been infected.

It’s worth noting that there’s legitimate doubt about whether the Chinese government is accurately reporting the extent of the virus’ impact. At least eight people have been arrested by the Chinese government for spreading hoaxes, according to reporting from the Poynter Institute in January. On the popular Chinese social media app WeChat, some have said that frontline reports by medical workers are being taken down.

Still, the exact number of people infected by the coronavirus remains unknown.

False: A teen on TikTok is the first case in Canada

On TikTok, some teenagers have pretended to be infected with the virus. One student in Vancouver posted a popular video falsely claiming his friend had the first Canadian confirmed case of coronavirus. The video showed a teenager vomiting in school trash cans and wearing a mask around campus. In an interview with the Daily Beast, a spokesperson for the British Columbia Department of Health confirmed that the video is fake. At the time, the only confirmed case of coronavirus in British Columbia, at the time of the video was posted, was a man in his 40s.

TikTok appears to have deleted the original viral video which had over 4.1 million views, but a similar video, posted by the same user, showed a teen alleging a classmate had contracted the virus remained up as of February 20. That morning, the company said it released a feature directing users to trusted sources of information, like the WHO, when they search for coronavirus-related content in the app.

False: The Chinese government built a hospital overnight

It’s worth noting that the Chinese state media has also been spreading false information. As BuzzFeed News first pointed out, two state media outlets — Global Times and People’s Daily — circulated an image of a newly constructed building and claimed it was a hospital in Wuhan that was constructed in just 16 hours. In fact, the building in the image was an apartment building more than 600 miles away.

This is just one example of how the Chinese government and state-backed organizations have used false or misleading information to portray the outbreak as being under control.

How tech platforms are responding

Every social media company Recode reached said they were working to reduce the impact of false information about the coronavirus in some way, to varying extents.

In addition to taking down conspiracy theories and provided WHO free advertising, Facebook said it’s also working on “blocking people from running ads that try to exploit the situation.” Zuckerberg said, as an example, that would include a company promoting a product that claimed to cure a disease. He also said,: “Researchers are already using aggregated and anonymized Facebook data — including mobility data and population density maps — to better understand how the virus is spreading.

In a statement, Twitter appeared to echo some of the latest steps being taken by Facebook. The company said it would “halt any attempt by advertisers to opportunistically use the Covid-19 outbreak to target inappropriate ads,” that it was working with fact checkers to promote accurate content on the site, and that it was also supplying data to researchers.

Twitter also said it’s not “seeing significant coordinated platform manipulation efforts around these issues.” This doesn’t mean that there’s not false information about coronavirus on Twitter, as the hoaxes we mentioned earlier prove. Twitter’s response simply indicates that the company hasn’t found any evidence of intentional disinformation campaigns by someone, like a state actor or political group.

In the early days of the outbreak, Facebook’s approach was to put fact-checking alerts on false content related to conspiracy theories. But at the end of January, the company announced that it would take additional action:

We will also start to remove content with false claims or conspiracy theories that have been flagged by leading global health organizations and local health authorities that could cause harm to people who believe them. We are doing this as an extension of our existing policies to remove content that could cause physical harm. We’re focusing on claims that are designed to discourage treatment or taking appropriate precautions. This includes claims related to false cures or prevention methods — like drinking bleach cures the coronavirus — or claims that create confusion about health resources that are available. We will also block or restrict hashtags used to spread misinformation on Instagram, and are conducting proactive sweeps to find and remove as much of this content as we can.

Twitter has also placed a warning label linking to the CDC when users search “coronavirus.”

Meanwhile, starting in late January, TikTok began issuing a notification for users when they search for the “coronavirus” hashtag in the app. The alert encourages users to look to “trusted sources” like the WHO for accurate information and to report content that might violate its community guidelines. TikTok told Recode in a statement that its guidelines “do not permit misinformation that could cause harm to our community or the larger public,” adding that “[w]hile we encourage our users to have respectful conversations about the subjects that matter to them, we remove deliberate attempts to misrepresent authoritative sources of news.”

YouTube has its own version of an advisory. Beginning in late January, the video platform began showing short previews of text-based news articles about the coronavirus in search results. If you search “coronavirus” on YouTube, for example, you’re linked to a WHO landing page about the novel coronavirus. YouTube told Recode that false information generally does not violate the platform’s rules unless it involves hate speech, harassment, scams, or inciting violence. The company also said it aims to reduce the recommendations of what it deems “borderline content” or videos that could misinform users in harmful ways — including false information about coronavirus.

Despite these efforts, it’s seemingly impossible for these platforms to take down every false coronavirus post as soon as one pops up. As with any kind of misinformation, it’s a game of never-ending whack-a-mole. But the continued prevalence of false info about the outbreak, one month into its existence, shows how essential it is to contain the spread of misinformation, especially with serious health consequences involved.

Update March 4: This post has updated throughout with more examples of hoaxes as well as new information on the outbreak and tech company responses.