> 2. cameras can hash / sign every other frame or similar - we can build a chain of hardware to image that can be followed - and of an image or video does not have a CA cert chain it should be as mis-trusted as a web site without TLS

Sure! Also, by total coincidence, now it's possible to trace every single photograph ever taken to whoever took it. A bunch of photojournalists in Syria, Iran, Mexico, and Missouri go missing, but I'm sure that's a coincidence.

Traceability is not without its drawbacks.