WASHINGTON (NewsNation Now) — The CEOs of social media giants Facebook, Twitter and Google appeared before Congress Thursday to answer questions focused on their efforts to prevent their platforms from spreading falsehoods and inciting violence.

That’s been a familiar theme for lawmakers over the past few years. But the pressure is even higher following the Jan. 6 insurrection at the U.S. Capitol, the rise in COVID vaccine misinformation and united Democratic control of Congress and the White House. The latter could make legislative action more likely, although it remains far from a sure thing.

Facebook CEO Mark Zuckerberg; Sundar Pichai, chief executive of Google parent Alphabet Inc; and Twitter Inc CEO Jack Dorsey are testifying before the joint hearing by two subcommittees of the House Energy and Commerce Committee.

While the hearing is virtual, advocacy group SumOfUs erected cut-outs of the three CEOs dressed as Jan. 6 rioters on the National Mall near the Capitol. One showed Zuckerberg as the “QAnon Shaman,” a shirtless rioter wearing horns.

Lawmakers began the hearing by criticizing the social media platforms for their role in the riot and in the spread of COVID-19 vaccine misinformation, as well as concerns about children’s mental health.

“You failed to meaningfully change after your platform has played a role in fomenting insurrection and abetting the spread of the virus and trampling American civil liberties,” said Rep. Frank Pallone (D-NJ), chair of the Energy and Commerce committee.

“Your business model itself has become the problem and the time for self-regulation is over. It’s time we legislate to hold you accountable,” he added.

Some lawmakers are calling for Section 230 of the Communications Decency Act, which shields online platforms from liability over user content, to be scrapped or rejigged. There are several pieces of legislation from Democrats to reform Section 230 that are doing the rounds in Congress, though progress has been slow. Several Republican lawmakers have also been pushing separately to scrap the law entirely.

In written testimony released on Wednesday, Facebook argued that Section 230 should be redone to allow companies immunity from liability for what users put on their platforms only if they follow best practices for removing damaging material.

Facebook’s Zuckerberg said polarization in the country was not the fault of social media: “I believe that the division we see today is primarily the result of a political and media environment that drives Americans apart.”

Republicans on the panel also criticized the tech giants for what they see as efforts to stifle conservative voices.

Former President Donald Trump was banned by Twitter over inciting violence around Jan. 6. Facebook hasn’t yet decided whether it will banish the former president permanently. The company punted that decision to its quasi-independent Oversight Board — sort of a Supreme Court of Facebook enforcement — which is expected to rule on the matter next month. He is still suspended from YouTube.

The three CEOs have all appeared in front of Congress before, with Facebook’s Zuckerberg clocking up seven appearances since 2018.

Lawmakers’ scrutiny of misinformation on major online platforms intensified after U.S. intelligence agencies said Russia used them to interfere in the 2016 presidential election.

Last year saw false narratives about voter fraud that spurred Trump supporters to organize online and come to Washington on Jan. 6, as well as untruths about the severity of the coronavirus pandemic, bogus treatments for the coronavirus and the safety of vaccinations.

The Associated Press and Reuters contributed to this report.