A new report says hundreds of posts spreading misinformation about coronavirus are being posted online.
The Center for Countering Digital Hate has revealed that 649 posts were reported to Facebook and Twitter, and 90 percent of the posts remained visible online afterwards - and they didn't feature any warnings.
However, Facebook has hit back at the study, insisting the sample was "not representative".
A spokesperson for the social media company explained: "We are taking aggressive steps to remove harmful misinformation from our platforms and have removed hundreds of thousands of these posts, including claims about false cures.
"During March and April we placed warning labels on around 90 million pieces of content related to Covid-19 and these labels stopped people viewing the original content 95 percent of the time.
"We will notify anyone who has liked, shared or commented on posts related to Covid-19 that we've since removed."
Meanwhile, Twitter said: "As we've said previously, we will not take enforcement action on every Tweet that contains incomplete or disputed information about Covid-19.
"Since introducing these new policies on March 18 and as we've doubled down on tech, our automated systems have challenged more than 4.3 million accounts which were targeting discussions around Covid-19 with spammy or manipulative behaviours."