Tom Hanks and Gayle King, a co-host of “CBS Mornings,” have separately warned their followers on social media that videos using artificial intelligence likenesses of them were being used for fraudulent advertisements.
“People keep sending me this video and asking about this product and I have NOTHING to do with this company,” Ms. King wrote on Instagram on Monday, attaching a video that she said had been manipulated from a legitimate post promoting her radio show on Aug. 31.
The doctored footage, which she shared with the words “Fake Video” stamped across it, showed Ms. King saying that her direct messages were “overflowing” and that people should “follow the link” to learn more about her weight loss “secret.”
“I’ve never heard of this product or used it!” she wrote. “Please don’t be fooled by these AI videos.”
It was not immediately clear what weight-loss product the ad was promoting or what company was behind it.
Mr. Hanks issued a similar warning on Saturday, saying that an advertisement for a dental plan using his likeness without his consent was fraudulent and based on an artificial intelligence version of him.
“Beware!!” he wrote on Instagram over a screen shot of the apparent ad. “There’s a video out there promoting some dental plan with an AI version of me. I have nothing to do with it.”
It was unclear what company had used Mr. Hanks’s likeness or what products it was promoting. Mr. Hanks did not tag the company or mention it by name. There was no evidence of the video anywhere on social media.
Representatives for Mr. Hanks declined to respond on Monday to questions about the ad, including whether he planned to take legal action or if he had requested that the ad be removed from social media.
In an email, a spokesman for Meta, Instagram’s parent company, did not comment directly on the ads but said that it was “against our policies to run ads that use public figures in a deceptive nature in order to try to scam people out of money.”
“We have put substantial resources towards tackling these kinds of ads and have improved our enforcement significantly, including suspending and deleting accounts, pages and ads that violate our policies,” the spokesman said.
Christa Robinson, a spokeswoman for CBS News, said in an email that Ms. King learned about the video featuring her likeness when friends called her attention to it. “Representatives on her behalf have requested the fake video be taken down several times,” Ms. Robinson said.
Lawyers for the entertainment companies came up with language that addressed guild concerns about A.I. and old scripts that studios own. Similarly, SAG-AFTRA, the union representing Hollywood actors that has been striking since July 14, is also concerned about A.I. It worries that the technology could be used to create digital replicas of actors without payment or approval.
Mr. Hanks spoke about the use of A.I. at length earlier this year, just days before the Hollywood writers’ strike began. He said on “The Adam Buxton Podcast” that he first used similar technology on the film “Polar Express,” which was released in 2004.
“We saw this coming,” he said. “We saw that there was going to be this ability in order to take zeros and ones inside a computer and turn it into a face and a character. Now that has only grown a billion-fold since then, and we see it everywhere.”
Mr. Hanks said the guilds, agencies and legal firms were all discussing the legal ramifications around an actor claiming his or her face and voice as intellectual property.
He mused that he could pitch a series of movies starring him at 32 years old. “Anybody can now recreate themselves at any age they are by way of A.I. or deep-fake technology,” he said.
“I could be hit by a bus tomorrow, and that’s it, but performances can go on,” he said. “And outside of the understanding that it’s been done with A.I. or deep-fake, there’ll be nothing to tell you that it’s not me and me alone. And it’s going to have some degree of lifelike quality. That’s certainly an artistic challenge, but it’s also a legal one.”
As A.I. begins to take root in various forms, and as companies begin experimenting with it, there are concerns about how confidential data might be handled, the accuracy of A.I.-generated answers and how the technology could be harnessed by criminals.
For now, there are more questions than answers. Policy experts and lawmakers signaled this summer that the United States was at the start of what will very likely be a long and difficult road toward the creation of rules regulating A.I.
Christine Hauser contributed reporting.