Two Democratic US senators on Thursday will add to the stack of bills going after Section 230 - a law that protects tech companies from being sued over content posted by users - making such platforms responsible for health-related misinformation.
The legislation introduced by Amy Klobuchar and Ben Ray Lujan requires internet platforms such as Facebook to take down health and vaccine-related misinformation during public health emergencies or be held liable for that failure.
It also directs the Department of Health & Human Services to issue guidelines on what constitutes health misinformation.
"These are some of the biggest, richest companies in the world and they must do more to prevent the spread of deadly vaccine misinformation," Klobuchar said.
The bill quotes a study from the Center for Countering Digital Hate that found social media platforms failed to act on 95% of coronavirus-related disinformation reported to them.
Kevin Martin, a vice president of public policy at Facebook, said the company supports reforming Section 230.
"We believe clarification on the difficult and urgent questions about health related misinformation would be helpful and look forward to working with Congress and the industry as we consider options for reform."
The Health Misinformation Act is not the first bill targeting tech firms' liability shield from Senator Klobuchar, who chairs the Senate antitrust subcommittee.
Earlier this year, she co-sponsored another bill called the Safe Tech Act with two fellow Democrats. It aims to make social media companies more accountable for enabling cyber-stalking, targeted harassment and discrimination on their platforms.
The chief executives of Google, Twitter and Facebook have said Section 230 is crucial to free expression on the internet. They said it gives them the tools to strike a balance between preserving free speech and moderating content, even as they appeared open to suggestions that law needs moderate changes.
Several Republican lawmakers have separately pushed to scrap the law entirely over decisions by tech platforms to moderate content critical of former President Donald Trump and his supporters.
There are several other pieces of legislation aimed at changing the law that have been making the rounds for over a year, including a bipartisan bill from Democrat Brian Schatz and Republican John Thune.
Trump repeatedly pushed for the legal protection to be stripped away over what he alleged was censorship against conservatives.