[kc0bfv]

But this only works if all views of the images employ your client... If I download an image (screenshot if necessary), modify it, and host it myself, how does the system work then?

And, unless all users trust only things viewed securely, and distrust things viewed nonsecurely (out of your client), then misinformation and fake photos can still propagate, right? (Or, how does the system handle this?)