I agree to some extent (and I'm excited by the progress in "opportunistic encryption"), but I'd like for people to also start thinking about what's possible and

I agree to some extent (and I'm excited by the progress in "opportunistic encryption"), but I'd like for people to also start thinking about what's possible and what's simply not. For example, modern block ciphers like AES can protect data against an attacker that does not have access to the encryption key. However, in this case we're talking about an attacker that has perhaps 90% of the encryption key, the UID, in its physical possession. The UID can be concealed in many ingenious ways, but that doesn't change the fact that the attacker is in physical possession of the atoms that encode it. This is essentially "security by obscurity", albeit on a high level. In contrast I would argue that message exchange over the internet can be made secure, even against a nationstate adversary.