Facebook CEO Mark Zuckerberg, Google CEO Sundar Pichai, and Twitter chief Jack Dorsey faced a panel of US lawmakers at a remote video hearing on Thursday looking for answers on how social media platforms are responsible for harmful content. 

Big tech has again come under pressure recently over the spread of coronavirus misinformation on social media platforms, as well as the platforms' role in helping fuel the storming of the US Capitol in January. 

There is increasing support in the US Congress for legislation to regulate social media platforms as lawmakers say increased political polarization and hate speech have reached dangerous levels. 

What did lawmakers say?

During the hearing by the House Energy and Commerce Committee, lawmakers grilled the three tech bosses, often interrupting their explanations and asking for yes or no answers as to whether social media companies bear some responsibility for the Capitol riot. 

"Your business model itself has become the problem. The time for self-regulation is over. It's time we legislate to hold you accountable,'' said committee chairman, Democrat Frank Pallone. 

"It's now painfully clear that neither the market, nor public pressure, will enforce the social media companies to take the aggressive action they need to take to eliminate disinformation and extremism from their platforms," he added.

Possible legislation, which has bipartisan support, would include removing protections under a 25-year-old telecommunications law that keeps internet companies from being held liable for what users post.

Democrats have said social media is responsible for spreading misinformation during the 2020 election season, and allowing baseless "stop the steal" voter fraud claims touted former President Donald Trump to spread, which eventually led to the Capitol attack.

Mike Doyle, a Pennsylvania Democrat, told the CEOs that the attack and "the movement that motivated it started and was nourished on your platforms.''

How did tech bosses respond?

Twitter's Dorsey was the only CEO to reply "yes" to the Capitol question, adding that the "broader ecosystem" had to be accounted for. 

Zuckerberg from Facebook said his company has built "effective systems" and said the rioters and Trump were to blame.  

Google's Pichai said it was a "complex" question, but that Google always feels a sense of responsibility. 

All three defended their companies' efforts to remove hate speech and disinformation circulated on their platforms, whiling balancing this regulation with freedom of speech. 

"I don't think we should be the arbiters of truth and I don't think the government should be either,'' Dorsey said.

"We believe in free expression, we believe in free debate and conversation to find the truth," he added. 

"We always feel some sense of responsibility,'' said Pichai.

Zuckerberg said the issues were "nuanced'' and "people often say things that aren't verifiably true, but that speak to their lived experiences," adding that it would be a mistake to limit people's ability to share experiences. 

However, the Facebook founder said also said he didn't want "misinformation to spread that undermines confidence in vaccines, stops people from voting, or causes other harms."

 "Any system can make mistakes'' in moderating harmful material, he added.

wmr/rc (AFP, Reuters, AP)