Manipulated videos of Speaker Nancy Pelosi that made it seem as if she were stumbling over and slurring her words continued to spread across social media today, fueled by President Trump’s feud with the Democratic leader.
One of the videos, which showed Pelosi speaking at a conference this week, was slowed down and edited to make her speech sound continually garbled.
The video has been viewed millions of times on Facebook and was amplified by the president’s personal lawyer, Rudy Giuliani, who shared the video last night on Twitter.
“What is wrong with Nancy Pelosi?” Giuliani said in a tweet that has since been deleted. “Her speech pattern is bizarre.”
Trump himself tweeted a separate video of Pelosi last night, an edited clip from Fox Business that spliced together moments from a 20-minute news conference and emphasized points where she had stumbled on her words.
“PELOSI STAMMERS THROUGH NEWS CONFERENCE,” the president tweeted.
By Friday, the social media giants, already under pressure to fight online disinformation, were forced to respond.
Addressing the distorted video that made Pelosi’s speech sound slurred, YouTube said the video violated its standards and had been removed.
Facebook said that a third-party fact checker had rated the video “false,” but posts remained on the site and the company said it was trying to limit how widely the video was shared.
That video continued to be shared and viewed on Twitter, but the company declined to comment.
The videos surfaced online amid a particularly intense and public feud between Trump and Pelosi.
Each questioned the other’s temperament and mental fitness in an exchange of personal insults on Thursday, as Pelosi works to stave off impeachment proceedings that she believes could harm her party and as Trump continues to defy Democratic efforts to subpoena documents and summon witnesses in the wake of the release of the special counsel’s report last month.
But the videos also raised broader concerns about the roles of digital manipulation and disinformation in politics, particularly in the lead-up to the 2020 election.
Tech giants have been grappling with how to combat disinformation, after Russian interference during the 2016 presidential election became a template for spreading false information online.
And recent episodes have underscored how videos and other information can make their way from the corners of the internet to the mantel of national politics.
Trump has previously used doctored, if obviously cartoonish, videos for political purposes, including ones targeting former Vice President Joe Biden, a Democratic candidate for president, and CNN, the cable news network.
In another case, his administration relied on a misleadingly edited video from a contributor to the conspiracy site Infowars to help justify removing the credentials of CNN’s chief White House correspondent.
The origin of the footage that changed Ms. Pelosi’s speech was not clear.
In a video posted by C-SPAN, she can be seen speaking at normal speed at a conference for the Center for American Progress.
Siwei Lyu, a professor of computer science at the State University of New York at Albany, said the video boosted low frequencies in the audio, while preserving Pelosi’s words and appearance, making it especially effective at creating a false impression.
“It’s very subtle,” he said. “I think that is actually one of the most dangerous parts of disinformation and fake media.”