One really dangerous thing about it is that once you send something it just won't disappear.
What happens on the Internet stays on the Internet and all that, but no reason to write everything in stone - especially in times and places where governments thinks it is a good idea to cut Internet.
It's not that black and white. Some communicators for example delete messages after a specified time and don't archive by default. It's not perfect, and it's not supposed to be. But it still raises the bar a bit - if your peer is not compromised, you can at least hope the history goes away.
Same could be done with "permanent" message by rotating shared encryption keys and discarding old ones for example, so you can build something with better privacy on top.
>It's not that black and white. Some communicators for example delete messages after a specified time and don't archive by default. It's not perfect, and it's not supposed to be
If something is not secure you can forget it by default, there is NO information system than can securely delete and protect it's delivered end user information, no DRM no Snapchat nothing, the consumed and delivered message can always be seen.
Scrub the information and rotate encryption keys with enforced deletion.
Sure, this would not get around a dedicated attacker, or screenshotting, but that's the same as printed information, or information transfer over radio. Someone can always listen in if they have enough resources and time. Even closed networks can be infiltrated with enough persistence.
First, that's why I wrote "hope" and mentioned it's not perfect. But "the consumed and delivered message can always be seen" is just incorrect. IF both sides destroy either the message or the encryption keys for it, then no, it can't be seen. (Just the metadata about it being sent)
Your thinking is too narrow, i just make a screenshot of your message, or filming your Video from the Screen, that's what i mean by 'consumed', but yes if both party's delete the message normal encryption is enough even 'just' with forward secrecy, but the metadata is often much more interesting (even the NSA said that).
What happens on the Internet stays on the Internet and all that, but no reason to write everything in stone - especially in times and places where governments thinks it is a good idea to cut Internet.