Now that they've broken the ability to trust video, they're looking to build it back, as long as you're allowed to use the tools:

https://blog.google/innovation-and-ai/products/identifying-a...

(and the previous SynthID: https://deepmind.google/blog/identifying-ai-generated-images...)

But it very much is "close the barn door after the horse has bolted and the barn has otherwise burned down".