That's a reasonable point I suppose, although a private Matrix server is just a fat peer from this perspective. Unless its database lasts 50 years, those messag

That's a reasonable point I suppose, although a private Matrix server is just a fat peer from this perspective. Unless its database lasts 50 years, those messages are just as gone, and Matrix (I think?) uses TLS in addition to E2E. Score a point for urbit I guess: any channel is limited to those peers participating in it, so Mallory would have to get her hands on one of the planets which received the messages. There is no central point of failure because there is no privileged server.