> you know they were the only ones to ever read it, This is the problem. If you could prove that they're the only ones that ever read it, it'd be great. But i

> you know they were the only ones to ever read it, This is the problem. If you could prove that they're the only ones that ever read it, it'd be great. But it's data hosted on someone else's closed source service most likely running on a VPS somewhere that yet another third party entity is running, connecting to your browser over unencrypted HTTP.