Wont just post it from an official social media account belonging to that journalist fix this issue ?

It starts off with opt in, then they do an update to now opt out, then then do an update to make it harder to opt-out and next thing we know this is something everyone has to live with.

How do we know evidence is valid in a court case? Chain of custody and documentation. Add to that some commitment scheme and trusted time-stamping and publish in real time and you are most of the way there to extremely veridical publishing.

But the main problem is the people most vulnerable to fake media are already bamboozled by bad Photoshop jobs. I don't see how any signing scheme will help.

The Journalism Industry has solved the "trust" problem decades ago. This isn't the problem the CCPA is trying to solve.