Whether it be deletions, blocks, or encryption people should be informed that once information is out, there is no guarantee. Mechanisms to stop duplication can give a false sense of security for the uninformed… if they’re not informed.

I do like the idea of the sender being able to tag something that is “intended to be confidential”. And I’d likely choose a client that enforced this automatically.

Deletion requests are great too, but should be labeled in some way as “requests”. No guarantee.

If it’s decentralized we must expect a market to arise for surveillance and marketing. I’m not saying we shouldn’t have tools to thwart this, but we should lead with education & personal responsibility.