I was thinking about how hard it is to accurately determine whether a screenshot posted online is real or not. I’m thinking there could be an option in the browser to take a “secure screenshot”, which would tag the screenshot with the date, url, and whether the page was modified on your computer. It could then hash both the tag and the image data and automatically upload this hash to some secure server somehow. There would need to be a way to guarantee that only the browser could do this, or at least some way to tell exactly what the source was. I’m not much of a cryptography person, but I would be surprised if it isn’t possible to do this. Then, you could check if the screenshot you see is legitimate by seeing if it’s hash exists in the list of real hashes.
The browser would also have to guarantee that you yourself didn’t edit the website. It’s not supposed to insure that the content was real, only that that website really had that content on it.