And what happens when someone surfaces a video of you spouting off racial slurs or running down a street naked, generated literally with a simple text prompt? Do you think your employer, colleague, or even spouse will take the repetitional risk of sticking around even if the video is completely AI-generated?
Every piece of communication will have to be signed to verify authenticity.
Camera makers are already looking into embedding authentication technology at the hardware level.
All a digital signature can prove is possession of a secret, it can't prove that some process was followed in generating an image.
It's impractical to have authenticity enforced by millions of consumer devices. If any random manufacturer in a third-world country can generate millions of valid signing keys to be embedded in millions of cheap phones or cameras, then there are many employees there that can also leak a bunch of valid keys if the price is right, and these keys can sign anything in a way that's indistinguishable from all these cheap cameras. And if you revoke the signatures of any "untrustworthy" manufacturers (really, any manufacturer can be and will be compromised, especially if some governments want to manufacture propaganda), then people won't stop using the phones/cameras just because their signatures aren't considered kosher, you'll still have millions of people uploading genuine, valid images from these cameras, so either people will have to trust invalid signatures or refuse lots of benign content, and I'll bet most people will choose the former one.
And of course a camera doesn't know if it's taking a picture of reality or another picture - it would take a relatively simple optical setup to allow any camera to record (and sign) an image off of another screen, so if some authenticity-verification system was actually working and popular, any reasonable criminals would do it and have signed recordings of their deepfakes from a real major brand camera.
Where exactly does this video "surface"? A random person on the internet?
If it's someone you know, with a reputation that makes them believable, then that's basically a criminal act and depends heavily on that person's reputation. There should be enough deference even without that, beyond simple harassment (which is what you're saying, where you lose your job or relationships).
Otherwise I'm not sure why your spouse or boss would rather believe some video coming from barelycartwheel48292@gmail.com is more believable than the person themselves.
Anyway, I was talking about overt scams not the wider cultural/social implications. This is a large new burden that will be imposed on society. We will learn to adapt and society will manage.
Every piece of communication will have to be signed to verify authenticity.
Camera makers are already looking into embedding authentication technology at the hardware level.
It's an inevitability.