If your doctor slips up and emails you about your AZT prescription, it doesn't matter how careful you were about not disclosing your HIV status over email you sent.
with criminal repercussions
Or better: don't use email and don't give an email address out to people who hold your secrets.
Not everyone is tech savvy. Not everyone understands encryption. Not everyone makes rational choices all the time.
Does that mean everybody should suffer the consequences of an arguably unintentional side effect of the technical implementation of DKIM?
> Does that mean everybody should suffer the consequences of an arguably unintentional side effect of the technical implementation of law?
Thankfully this is not law, but people should understand the things that can get them in serious trouble. A lot of legal concepts follow from basic principles and history.
Privacy concepts are the same way. It's simply not sufficient that we don't educate everyone about these things anymore. Ignorance isn't going to protect anyone from the fallout of misuse of technology.
The solution isn't to coddle people, it's to provide better technology that does the thing the way people intend to use it.
Do you send your social security number to people in emails?
Email has never been privileged communication and the problem isn't one of validation but one of not understanding one's level of privacy and risk. It uses relays without end-to-end encryption and there's no guarantee that what you sent is not totally out in the open.