What are deepfake porn videos from FakeApp and which celeb faces have been used by the AI tool?
The artificial intelligence software is worryingly free and easy to use for all internet users
A DARK piece of software allows users to superimpose the face of their favourite celeb onto an actress in a porn film.
Emma Watson, Arianna Grande and Taylor Swift are just some of the famous faces to have fallen victim to FakeApp, which has been downloaded more than 100,000 times.
Where did "deepfaking" and FakeApp come from?
Its origins can traced back to a single , who edited Wonder Woman star Gal Gadot's face onto a porn star's.
What frightened the online community is he did not seem to be a computer whizz, rather a Joe Bloggs using publicly available, Google-developed software.
Shortly after Motherboard outed him, he created a subreddit which quickly amassed tens of thousands of subscribers.
Another Reddit user pounced on this growing momentum by creating FakeApp, dubbed a "user-friendly" system which allows those with no computer knowledge to do exactly the same.
The videos have now reportedly spread to Pornhub and YouPorn.
How does FakeApp work?
FakeApp uses a "machine learning algorithm", a form of artificial intelligence, to create computer a generated version of someone's face.
First, it analyses hundreds of images and YouTube videos of the person whose face is to be mimicked.
It then goes through the video frame-by-frame, splicing the new subject's face onto the last one in a process that can take more than eight hours for a video a few minutes long.
The results can vary but if the two people have similar skin tone and physique, .
Which celebrities have fallen victim?
Given how easy FakeApp is to use, there's no saying how many people's faces have been manipulated into pornographic videos.
, including Jessica Alba whose face was put onto porn performer Melanie Rios' body by Reddit user UnobtrusiveBot.
Meanwhile nuttynutter6969 used FakeApp to superimpose Daisy Ridley's face onto another adult actress.
A fake Emma Watson was seen showering herself in another video which was falsely advertised as real.
Is "deepfaking" illegal?
It is certainly a violation but such apps could also be illegal, according to Andrew Murray, Professor of Law at the London School of Economics.
He told the Sun the actresses could sue for defamation should they be viewed "less favourably by members of society" as a result.
Murray added: "More likely such images could be viewed as forms of harassment, which they could report to the police."
Simon Miles, a partner at intellectual property specialists Edwin Coe, said such acts could also amount to "unlawful intrusion into the privacy of the particular celebrity".
Has it been used for anything other than porn?
Fortunately FakeApp has also been used to create non-pornographic footage.
And one of the unlikely stars of the easy-to-use app was screen legend Nicholas Cage.
For no reason other than "because they could", people started editing him into films was not in.
The latest on celebrity sex tapes
So if you ever wanted to see him Cage in Raiders of the Lost Ark or give a turn as Lois Lane in Superman - that footage exists.
In another hilarious video, German Chancellor Angela Merkel's face was replaced with that of Donald Trump.
And in a slightly offbeat move, Reddit user Z3ROCOOL22 combined footage of .