"Can Grandma read me The Wizard of Oz?" the boy asks hopefully. Soon, Grandma is speaking, the sound of her soft voice filling the room. 

But Grandma is not real. She is a deepfake. 

"Creepy." "Morbid." These were some of the reactions on Twitter last week after tech giant Amazon announced plans to bring back the voices of the dead as deepfakes.

At a conference in Las Vegas, AlexaA virtual assistant technology system used by more than 100 million people.  executive Rohit PrasadPrasad is Alexa's Senior Vice President and Head Scientist.  showed tech enthusiasts a demo of the new product.

Deepfakes are produced with a technology called "deep learning", which uses neural networks that mimic the human brain. Artificial intelligence (AIA computer programme that has been designed to think. ) programmes can be fed images of a person, and can then produce footage of almost anyone saying or doing anything. 

The clip of Grandma reading her grandson a bedtime story could be made with just one minute of sample speech. 

"We are unquestionably living in the golden era of AI, where our dreams and science fiction are becoming a reality," Prasad declared.

There is no doubt: deepfakes are on the rise. According to one report, the number of deepfakes available online doubles every six months. Internet users are responding. One viral TikTok account featuring deepfakes of actress Margot Robbie stubbing her toe and scrubbing a floor has 1.7 million likes. 

But unlike Prasad, not everyone thinks deepfakes are the stuff of dreams. Instead, many worry that we are descending into an AI nightmare. 

The technology has many legitimate uses. Deepfakes are used in filmmaking, e-commerce and video games. But there are more sinister deepfakes out there too.

Already, criminals have used the technology to commit fraud and even superimpose unwitting victims onto pornographic images. And now, some fear they could be used to influence politics too. 

In March, a video of Ukrainian president Volodymyr Zelensky appeared online. He told the Ukrainian army to surrender to Russian forces - or so viewers thought. The video was a deepfake.

Three years previously, then US president Donald Trump tweeted a video of Democrat politician Nancy Pelosi slurring her words. This, too, was not real. It was a "cheapfake", a video made using simpler programs. 

But sophisticated technology means that deepfakes are getting better and harder to spot.

"They take the threat of fake news even higher, as seemingly anyone can now have the ability to literally and convincingly put words in someone else's mouth," says Gil Becker, CEO of content platform Anyclip.

According to the World Economic Forum, deepfakes are increasingly going to "challenge our trust in reality".

They could be used to discredit honest politicians, or give leaders an excuse to dismiss reality as fake news.

Now, policymakers are searching for answers. In May, the Austrian government published an action plan to tackle deepfakes and raise awareness of false videos.

Many believe action cannot come soon enough. If it does not, some fear we could lose our ability to separate fact from fiction forever. 

Yes: Democracy is based on a shared understanding of the truth. But we can no longer trust our eyes and ears. In the future, the truth will be subjective, used by different tribes against each other.

No: Doctored footage is nothing new. In the world of fake news, we already know to be sceptical of what we see online. This could be the wake-up call we need to restore truth and trust to politics. 

Or... With more laws and guidance in place to regulate how they are used, deepfakes could be a blessing for a society, not a curse. They are already transforming media and entertainment for the better.