The coronavirus pandemic has inspired a flood of misinformation and disinformation ranging from ineffective health advice to dangerous and divisive conspiracy theories causing real-world violence, such as attacks against telecommunications engineers.

The London-based Center for Countering Digital Hate worked with 10 volunteers from youth action group Restless Development to find Facebook, Instagram, and Twitter posts containing coronavirus misinformation between 20 April and 26 May. They reported 649 posts which appeared to contain misinformation violating the platforms’ own rules.

Some of these posts promoted bad science (such as that viruses cannot be transmitted through air or that viruses have never killed anybody), false cures (such as Vitamin C and D supplements), and false warnings (such as that wearing a face mask causes cancer). Other posts contained baseless conspiracy theories connecting the coronavirus pandemic to the rollout of 5G technology, claiming that the virus does not exist, or claiming that the pandemic is caused by vaccinations. Many attacked Microsoft co-founder and health research donor Bill Gates.

According to the report [PDF], 90.6 per cent of the posts were not acted upon. Of the 61 posts which were acted upon, 41 were removed, six were flagged as false information, and 12 led to accounts being closed.

Twitter was the least responsive platform in the study, taking action against just three per cent of the 179 posts reported. Facebook acted on 12 per cent of the reported posts and Instagram (also owned by Facebook Inc) acted on 10 per cent.

The volunteers expressed frustration and surprise with their findings, with one commenting: “It’s frustrating to see that [platforms are] allowing harmful misinformation to be spread so easily – especially when posts are being directly reported to them.”

Center for Countering Digital Hate CEO Imran Ahmed said: “Social media giants are shirking their responsibility to stop dangerous misinformation spreading. Their systems for reporting misinformation and dealing with it are simply not fit for purpose.”

“Social media giants have claimed many times that they are taking Covid-related misinformation seriously, but this new research shows that even when they are handed the posts promoting misinformation, they fail to take action.”

Ahmed suggested that if social media companies continue to fail to act on misinformation, lawmakers should hold them to account with financial sanctions reflecting the widespread cost of misinformation.

The shadow culture secretary Jo Stevens said: “This report exposes yet again the reality of what the global tech companies promise on removing harmful content and the pitiful steps they actually take in practice. Combating the impact of the global Covid-19 crisis is difficult enough, without the uncontrolled spread of extremely harmful content on social media platforms.”

Social media companies have promised lawmakers that they will proactively take on coronavirus misinformation. Twitter aims to insert a link to a page full of verified information beneath all misleading and false tweets about the virus; Facebook has promised to remove false claims about the virus and to direct users towards trusted sources of health information such as the WHO when they search for coronavirus-related terms; and YouTube has said that it will remove coronavirus-related content which contradicts WHO advice.

Despite these pledges, a considerable volume of coronavirus misinformation and disinformation remains online. A recent study estimated that a quarter of the most popular coronavirus-related YouTube videos contains misleading claims, while research indicates that around half of UK citizens have been exposed to false claims about the virus.