ActivityPub lets you address a post to your followers (a special collection), or a specific list ("enthusiasts").
Question: we're typically looking at identity as monolithic. Is there support for separability? ActivityPub has a "profile" object, can set up differnet profiles for different community. Or create different actors you don't tie together. Sometimes people on Mastodon create different users for different aspects.
Mailing lists are Pretty Good. If we could use that model as a basis ... the reddit of 10 years ago was a nice community before it became big, and even today there are nice subreddits - just not on the home page. r/math is always civil!
What are you looking for in distributed social networks?
A place to have discussions about governance and civic policy, with different viewpoints. Could run own system, but who would use it?
Chris: we've seen some success with people setting up interest-focused servers. But, another approach would be to build collections of people with an interest. ActivityPub allows collections of users (kind of like mailing lists)
Most of our server tooling has baked in the assumption that you've got a team of people running the tools.
Running these systems is still hard. The devops is challenging, but even harder are the user aspects. There may be ways to make it easier.
Scuttlebutt hybrid model has advantages: I get to choose who to sync with (web-of-trust-like). Also, it's offline; and focused on running on desktops (not just servers). But, it hasn't taken off, so hard to know.
Could Mastodon scale to billions of users? It's federated, like email, so yes. Then again, email's recentralizing - how many people run their own email servers. That's a risk too. Google Talk made XMPP/Jabber huge; and then they abandoned it, so my buddy list is now tiny. Fear #1 is how easy it can be to become complacent. Abuse seems easier to handle in centralized systems (although FB et al do really badly at it).
We've talked about doing end-to-end encryption. But there are complications: if I like something, the server wants to know how many likes there are. "Where I'd like things to go is less servers, and people running their own nodes." Move closer to a web of trust.
Deletion? It's a challenge - no guarantees. Also, immutability brings up challenging problems in general. Imagine on git where a trans developer changes their name ... now all the old commit logs have their deadname.
Back to questions about what happens when a server goes down. Is there any way to recover? Story isn't great (although with warning, as is the case with witches.town, it's not horrible). Content-based addressing could help - if posts were on IPFS, even if the user disappears, it still be accessible.
Microtipping? (Sending small amounts of digital currency over the internet.) Steemit is an example. For anti-abuse, could have a public inbox that has a small charge, family and friends have an inbox they can use for free. Helps with spam, doesn't help with targeted harassment.
Talking about problems when servers shut down. The network survives (unlike say when Geocities shut down) but it's still a challenge. Decentralized identity would let you move more easily.
Question about anti-abuse: what's there now? "Block" activity; and Mastodon has some additional facilities. Chris' view: users need the right to filter, as a complement to freedom of speech.