A doctored video of House Speaker Nancy Pelosi, in which she appears to be impaired, made the rounds on social media this week, picking up more than 2.5 million views on Facebook and demonstrating the power of what's called "deepfakes."

Hany Farid, a professor of computer science at the University of California Berkeley, told CBS News' Jeff Pegues that this video is just the tip of the iceberg of how videos and images can be manipulated.

"The video is really a pretty low tech fake," Farid said. "Most standard one is to take an image or a video of a person, candidate a president, and alter it to make it look like they are saying something that they never said."

The use of altered videos has led U.S. intelligence officials to issue a warning ahead of the 2020 elections. This year's Worldwide Threat Assessment said "adversaries and strategic competitors would likely attempt to use deepfakes" to influence campaigns in the U.S. but they could also be used for other nefarious reasons.

"What if somebody creates a video of President Trump saying, 'I've launched nuclear weapons against Iran, or North Korea, or Russia?' We don't have hours or days to figure out if it's real or not," Farid said.

"The implications of getting that wrong are phenomenally high. What you have to understand about this technology, is that it's not in the hands of few, it's in the hands of many."

President Trump tweeted out a separate edited video of Pelosi this week that appeared on Fox Business Network. The video, which pulls parts from Pelosi's Thursday press conference, in which she suggested Mr. Trump's staff or family should stage an intervention, is edited to heighten and highlight any verbal missteps.

"PELOSI STAMMERS THROUGH NEWS CONFERENCE," Mr. Trump tweeted, paraphrasing the headline Fox Business displayed.

Facebook said it is reducing its distribution of the Pelosi video but that it doesn't have a policy that stipulates that information you post must be true. YouTube has removed the Pelosi videos.