Just this week, two of the most famous people on the planet, actor Tom Hanks and YouTube star MrBeast, have been the subject of deepfake images used to sell products.

This week an artificially generated video of MrBeast—real name Jimmy Donaldson—began circulating on TikTok.

In the clip Donaldson, who rakes in $82 million a year according to Forbes, seemingly tells the viewer they are one of 10,000 “lucky” people to have been selected to win an iPhone 15 Pro, a new release that Apple launched last month.

In the video Donaldson claims winners have to pay just $2 for the device, which retails for $999.

The video, which appeared under a “MrBeast” username—complete with an apparent blue authentication mark—features the YouTuber’s likeness saying: “I’m MrBeast, and I’m doing the world’s largest iPhone 15 giveaway.”

The avatar in the video, which also speaks in Donaldson’s voice, asks viewers to click on a link attached to the video in order to “claim” their prize.

Donaldson, who has 189 million subscribers on YouTube, has made a name for himself courtesy of his extravagant giveaways—for example, helping 1,000 people hear for the first time and helping 1,000 blind people see for the first time—which may have led some viewers to think the video was real.

But Donaldson turned to his more than 24 million followers on X—the site formerly known as Twitter—to warn them about the scam.

“Lots of people are getting this deepfake scam ad of me,” the 25-year-old wrote. “Are social media platforms ready to handle the rise of AI deepfakes? This is a serious problem.”

Lots of people are getting this deepfake scam ad of me… are social media platforms ready to handle the rise of AI deepfakes? This is a serious problem pic.twitter.com/llkhxswQSw

— MrBeast (@MrBeast) October 3, 2023

TikTok did not immediately respond to Fortune’s request for comment, but told other outlets the ad and account had been removed from the platform within hours.

The platform has promised to crack down on deepfake images and videos. In March, TikTok’s updated policy said all images which are deepfake or manipulated, but replicate a realistic scenario, must be labeled as such.

The short-video site also banned deepfakes of private figures or young people, while manipulated images of public figures are allowed but only for artistic or educational content.

The Tom Hanks dental plan

Forrest Gump and Toy Story star Tom Hanks experienced a similar incident this week.

This weekend, the Oscar-nominated actor posted on his Instagram page that his likeness was being used in an AI advert for a dental plan.

“Beware!” Hanks wrote. “There’s a video out there promoting some dental plan with an AI version of me. I have nothing to do with it.”

As well as customers potentially losing money on products or scams, celebrities who are having their images manipulated by deepfake artists say it’s “scary” to witness.

CBS news presenter Gayle King spoke this week about her confusion when people began getting in touch with her about weight-loss gummies.

It emerged that a clip King used to promote her podcast Gayle King in the House had been doctored with a voiceover, appearing to show the public figure endorsing the product.

“I’ve never taken the gummies—I don’t even know what this is about,” King told CBS Mornings. “It’s very scary, it can have you saying anything.”

Even those who have been bullish on AI, like Microsoft cofounder Bill Gates and JPMorgan Chase CEO Jamie Dimon, have said they worry about the technology falling into the wrong hands.

Gates made his fears known in a blog post in July, but Dimon’s comments came more recently, telling Bloomberg TV: “Technology has done unbelievable things for mankind, but, you know, planes crash, pharmaceuticals get misused—there are negatives.

“This one, the biggest negative in my view, is AI being used by bad people to do bad things. Think of cyber warfare.”