If it's a video and one is viewing it after the incident, what can one do?

This technology isn't dangerous. The true danger is the reaction from the public. That's the weapon being used.

Now, what would it take to destroy someone? Toronto mayor was caught smoking crack on video. Fake material surfacing left and right, suddenly every public figure is smoking crack? It becomes theatre at that point and when a real video surfaces, nobody will believe it. So that takes some of the power away from these deep fakes if used nefariously. So they'd have to up the ante. Well, it's going to be really hard to circulate material involving sexual acts with... things you're not supposed to be doing that with. At that point, you wouldn't need the video. All you'd need is the media to claim it happened. So it's really not that much more dangerous than how things might already be.

Apologies for the rushed response. It's something I've been thinking a lot about and the thoughts are still a bit scattered. I realize it's... not that easy.