The CEOs of Facebook and Twitter are being summoned before Congress to defend their handling of disinformation in the 2020 presidential election.
Prominent Republican senators have refused to knock down President Donald Trump's unfounded claims of voting irregularities and fraud, even as misinformation disputing Democrat Joe Biden's victory has flourished online.
Sen Lindsey Graham, a close Trump ally who heads the Senate Judiciary Committee where the CEOs will testify Tuesday, has publicly urged, "Do not concede, Mr. President. Fight hard."
Both Facebook's Mark Zuckerberg and Twitter's Jack Dorsey promised lawmakers last month that they would aggressively guard their platforms from being manipulated by foreign governments or used to incite violence around the election results - and they followed through with high-profile steps that angered Trump and his supporters.
Twitter and Facebook have both slapped a misinformation label on some content from Trump, most notably his assertions linking voting by mail to fraud. On Monday, Twitter flagged Trump's tweet proclaiming "I won the Election!" with this note: "Official sources called this election differently."