It seems to me robots.txt or #nobot or a flag in the activitystream, or any advisory setting, isn't going to be more than a speed bump to abuse. In fact, it'll be a pain for ordinary users, while the folks with bot/troll armies will ignore that setting and index the fediverse as much as they want. And a "friend-locked" mode feels very restrictive. Maybe: friends-of-friends locked. Maybe some other social-graph algo. Maybe a TOS click-through legal tool.
@maiyannah I mostly agree with you, although I think there's still value in a 'trusted-people-only' setting. Yes, you're also trusting the instances those people use, but I think that's generally going to be an okay bet. At least, I'd like to give that a try. We do that for email, and it generally works okay.
ActivityPub supports this via collections of users. Maybe that's also what people want. (Mastodon and GNU Social don't yet but could.) We haven't emphasized it though in examples...
- aspects/circles: a collection of people addressed to by an individual: select sending this to only "family" or "coworkers"
- groups: more like open-subscription mailing lists
Both are "collections" of sorts, but how "who's in there" is managed is different.
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