Working out what is real and what is fake is about to get even harder, as celebrities turn up as porn actors and politicians say things they'd never dream of.
The phenomenon is being called deep fakes, because the face-swapping technology first emerged deep in the internet - and it's improving rapidly.
Victoria University expert in computational design Tom White said it can be hard to tell the difference between a deep fake and a real video.
One of his students made an early-stage face-swapping video two years ago, and he believes it's the first example of a deep fake.
Mr White is developing a technology called Face Mark, allowing people to voluntarily mark an 'F' watermark on digitally altered media.
But what can people do if they come across malicious, digitally altered videos?
"The most important thing is find out where it is and try and get it taken down because once it is on the internet it is going to be really hard to erase," Hudson Gavin Martin technology partner Edwin Lim said.
But if you can't stop it, then you can make a complaint under the Harmful Digital Communications Act. Designed originally to deal with revenge porn, it makes it an offence to cause serious emotional harm.
Those who can afford to could consider legal action and sue for defamation.