“Misinformation is a significant challenge, and one that we are working hard to address,” said Chris Brummitt, a Google spokesman. “We will study the bill to determine our next steps, and urge the government to allow for a full and transparent public consultation on the proposed legislation.”

Simon Milner, Facebook’s vice president for public policy in the Asia-Pacific region, said in a statement that the social network supported regulation that “strikes the right balance between reducing harm while protecting people’s rights to meaningful speech.”

“We are, however, concerned with aspects of the law that grant broad powers to the Singapore executive branch to compel us to remove content they deem to be false and proactively push a government notification to users,” he added.

Companies like Facebook, Google and Twitter were once lauded for leading free speech and public discourse into a new age. Now, they are more likely to be blamed for providing an outlet for misinformation.

As skepticism has risen, the platforms have taken measures to combat bogus or harmful information, with varying degrees of success. They have stepped up efforts to police content and enlisted the help of outside organizations to fact-check news articles and videos. They have tried to empower trusted publishers, such as traditional news agencies, to improve the overall quality of the information that users are shown.

But controversies have continued to erupt. And even for the internet companies, it may now be easier to ask lawmakers to lay down guidelines for content. That way, the companies can deflect the blame if the policies cause dissatisfaction.

In an op-ed over the weekend in The Washington Post, Mark Zuckerberg, Facebook’s chief executive, made a case for regulating his platform, calling for “a more active role for governments and regulators.”