Moderation: controlling your data

[hackergrrl]

Our new subjective moderation system is wonderful for hiding others, but doesn't address the need of a user who wishes for another (e.g. abusive) user to not be able to see them (their name or messages).

On a technical side, I would see this working outside -- kinda inverted! -- of the subjective moderation system. A person ought to have control over their own data, regardless of others' preferences. If I ran the command /vanish-from bob, I would expect both my client and everyone else's client to cease sending any of my feed messages to Bob. I'd perhaps also expect Bob's client to purge my data from his disk, assuming he hasn't modified his client to prevent this.