I'm not too worried about the effects of this technology in court cases -- as Argent suggests, proving the chain of evidence will become even more important, as will developing forensic techniques to detect this kind of forgery, and also video evidence is generally not the only evidence available.
Usually, at least in my experience, video evidence is most effective when it supplements other evidence. A police video, for example, recording a car chase makes the course of the incident much easier for everyone to follow, and similarly a video of a late night brawl is usually most useful in supplementing witness statements to make it easier to understand what was happening during a fast-moving, chaotic incident.
My main worry is that it simply helps the campaign to undermine trust and confidence in news-reporting altogether, since it makes it so much easier to question the authenticity of reports you don't like -- imagine, for example, if a video of Trump eventually surfaces purporting to be the infamous Moscow "pee tapes" or outtakes from The Apprentice showing him saying all manner of racist and sexist things, or a video purporting to show misconduct by military personnel or the police.
Whatever its authenticity, the whole thing is likely to turn into a huge argument about whether the video is fake or not, which will never get settled, and everyone ends up that bit less confident in the credibility of anything they see or read.
We've seen that already plenty of times, with heated arguments about the authenticity of what appear to be bona fide news clips of missile and bomb attacks in the Middle East, for example -- do they show genuine injuries and destruction or is it all staged?
"Truthers" will have a field day and everyone ends up not sure what to believe.
This rings all sorts of alarm bells. Maybe this is a flashback to my time, in an earlier life, as someone who spent a fair bit of time in Moscow and St Petersburg back in the "wild East" days just after the collapse of the USSR, but I really would suggest people read
Nothing is True and Everything is Possible: Adventures in Modern Russia by Peter Pomerantsev and then
The Road to Unfreedom: Russia, Europe, America by Timothy Snyder and consider the implications of this new technology -- you can bet there's some very smart people in Moscow and St P who are very excited about the implications of all this, and some not so smart people in the US with far more money than is good for them who are more then happy not only to, in a
phrase attributed to Lenin, sell them (the Bolsheviks) the rope with which to hang them (capitalists) but also give them the money with which to buy it.
From Chapter 5 of
The Road to Unfreedom:
[In the Russia of the 2010s] Ninety percent of Russians relied upon television for their news. Surkov was the head of public relations for Pervyi Kanal, the country’s most important channel, before he became a media manager for Boris Yeltsin and Vladimir Putin. He oversaw the transformation of Russian television from a true plurality representing various interests into a false plurality where images differed but the message was the same. In the mid-2010s, the state budget of Pervyi Kanal was about $850 million a year. Its employees and those of other Russian state networks were taught that power was real but that the facts of the world were not. Russia’s deputy minister of communications, Alexei Volin, described their career path: “They are going to work for The Man, and The Man will tell them what to write, what not to write, and how this or that thing should be written. And The Man has the right to do it, because he pays them.” Factuality was not a constraint: Gleb Pavlovsky, a leading political technologist, explained, “You can just say anything. Create realities.” International news came to substitute for regional and local news, which all but disappeared from television. Foreign coverage meant the daily registration of the eternal current of Western corruption, hypocrisy, and enmity. Nothing in Europe or America was worthy of emulation. True change was impossible—that was the message.
RT, Russia’s television propaganda sender for foreign audiences, had the same purpose: the suppression of knowledge that might inspire action, and the coaxing of emotion into inaction. It subverted the format of the news broadcast by its straight-faced embrace of baroque contradiction: inviting a Holocaust denier to speak and identifying him as a human rights activist; hosting a neo-Nazi and referring to him as a specialist on the Middle East. In the words of Vladimir Putin, RT was “funded by the government, so it cannot help but reflect the Russian government’s official position.” That position was the absence of a factual world, and the level of funding was about $400 million a year. Americans and Europeans found in the channel an amplifier of their own doubts—sometimes perfectly justified—in the truthfulness of their own leaders and the vitality of their own media. RT’s slogan, “Question More,” inspired an appetite for more uncertainty. It made no sense to question the factuality of what RT broadcast, since what it broadcast was the denial of factuality. As its director said: “There is no such thing as objective reporting.” RT wished to convey that all media lied, but that only RT was honest by not pretending to be truthful.
Factuality was replaced by a knowing cynicism that asked nothing of the viewer but the occasional nod before sleep.