[duchenne]

Yes, this system does not seem to prevent the information from spreading.

I guess that the logic is that most people who know how to make a screenshot also know how to make a fake screenshot.

So, let's say that Mr A is not a very honest guy. Moreover, Mr A has a sensitive document that could be a liability in court. He wants to share it with Mr B. But, he does not completely trust Mr B. With this system, he can share it. If Mr B sends a screenshot to the police or a judge, it will be easier for Mr A to claim that the screenshot is fake.

That's just a guess... I hope that it was not the intent of the dev, though.

[chronogram]

Even easier, right? Can’t B press F12 and change the content easily? One mail is not enough evidence.

A would be better off using something like Snapchat for the confidentiality.