Almost one-quarter of Americans say they’ve shared fake news, according to a poll that found widespread public concern about the problem of misinformation online.

The Pew Research Center survey released Thursday showed that nearly one-third of adults often encounter fake news online and about two-thirds believe the explosion of false information causes a “great deal of confusion about the basic facts of current issues and events.”

The findings add to the debate that’s raged since the election about the consequences of made-up articles on the internet and who should stop them. President Barack Obama and Pope Francis have condemned the spread of fake news. Social-media companies including Facebook Inc. have been criticized for the prominent role false stories received on their services in the run-up to the U.S. presidential election, potentially influencing its outcome.

While about 40 percent of adults said they very were confident they could spot fake news, 14 percent said they’ve shared a story they knew was fake at the time and 16 percent said they’ve shared a story they later realized was false, according to the Pew survey. The organization polled 1,002 adults from Dec. 1 to Dec. 4.

The survey found Americans about equally divided over who’s responsible for combating fake news, saying the government and the public, along with the tech giants that run social networks and search engines, should all do their part.

One fake news story before the election claimed that Donald Trump was endorsed by the Pope. Earlier this month, a man fired a rifle inside a Washington pizzeria and later told authorities that he was investigating a fake conspiracy story involving Hillary Clinton.

Many made-up articles are created by people looking to profit from the online advertising revenue generated from millions of clicks. Their work gets amplified on Facebook, resulting in calls for the social-media giant to do more to weed out fake stories.

Last month, Facebook Chief Executive Officer Mark Zuckerberg said his company is taking steps to address its role in spreading fake news, such as enlisting the help of third-party fact-checkers. Zuckerberg underscored the delicate balance his company must strike, saying “we need to be careful not to discourage sharing of opinions or mistakenly restricting accurate content.”