Yeah, though that particular complication is chain-of-custody like anything else, like you said. At some point the court has to trust evidence processing.

If (say) the defense wants to verify, they can ask the judge to scrub through original footage. This feels like a thing that could be smoothed out over time.

…But what worries me most is the ease of ‘spamming the system’. Say someone wanted to commit a crime pre-emptively, in front of devices doing this automatically; they’d have incentive to pay to flood the blockchain with random data. And if you introduce a small cyptocoin cost to uploading, well, that’s a whole can of worms you’ve opened there.