During a lively four-hour session of a congressional hearing on Wednesday, Senator Cory Gardner of Colorado asked Jack Dorsey, Chief Executive Officer of Twitter, why his company had flagged posts by United States President Donald Trump but not those of Iran’s Supreme Leader Ali Khamenei.

The Senate Commerce committee was reviewing US federal law on social media, specifically Section 230 of the 1996 Telecommunications Act, which deems that websites and service-providers are not publishers with legal responsibility for users’ post, while leaving it open for them to moderate content of posts.

“I just don’t understand how Twitter wants a world of less hate and misinformation while you simultaneously let the kind of content that the ayatollah has tweeted out to flourish,” Gardner said.

Many Republicans are alarmed that Twitter and Facebook have labelled or fact-checked some of Trump’s claims about Covid19 and the 2020 election. The social-media giants argue that misinformation could threaten public health or undermine the democratic process.

Following the republication of cartoons in France depicting the Prophet Mohammed, Khamenei asked on Twitter: “Why is it a crime to raise doubts about the Holocaust? Why should anyone who writes about such doubts be imprisoned while insulting the Prophet be allowed?”

Khamenei was contrasting laws in some European countries, including Germany, outlawing denial of the Jewish holocaust with the stress on freedom of speech over the Mohammed cartoons. The decision by French president Emmanuel Macron to bestow France’s highest honor, the Légion d’honneur, on Samuel Paty, the teacher decapitated after showing his class the cartoons, has added to anger across the Muslim world.

At the US senate committee, Republican senators criticized Twitter and Facebook for blocking or limiting the spread of allegations in Rupert Murdoch’s News York Post over the business dealings of Hunter Biden, son of Trump’s Democratic Party challenger Joe Biden.

Democratic Party senator Gary Peters pointed out that the right-wing group that recently planned to attack Michigan Governor Gretchen Whitmer had organized on Facebook. The lack of regulation of social media in the US has been highlighted both by incitements to violence, misinformation, and US intelligence reports that Russia uses social media to influence American politics.