The general philosophy right now in the ActivityPub admin space is to federate widely and weed out the baddies as they show themselves (thus the emphasis on "rejecting" bad actors).
Personally I think this is only going to work for a little while but if ActivityPub catches on, it's going to be as inundated with spam as email is (without any of our modern spam filters). Therefore I personally moderate my ActivityPub server by whitelisting a handpicked list of servers that I personally trust (which I knew about by having browsed discussion groups on this topic).
As for the scaling question, there are two layers to that: per-server and overall-network scaling.
Per-server scaling doesn't matter. All that matters is serving content that the users of that server find worthwhile. Whitelisting works fine for this, but discovery requires checking out different servers or having out-of-band knowledge of other servers. I think this is fine. People can promote servers they find worthwhile in all kinds of ways, same way as for example gamers find gaming clans.
Overall-network scaling is a function of how all admins decide to federate. Right now most admins federate widely so the overall network has scaled very quickly. But really this doesn't matter either because there's actually not necessarily any such thing as an "overall network". If you made a graph of all ActivityPub servers in the world, there might be multiple disconnected graphs and that's fine. If admins in those graphs have decided not to federate with each other, that's the system working as intended.
> That's basically how things like substack work
My understanding (but correct me if I'm wrong) is Substack is a central server where multiple authors can publish their work. Federated content is different in that I can publish my content on my server and anyone who federates it can also get it on their server (and likewise I can get theirs on mine). But if I go off the rails then they can cut me out while still federating other authors they find worthwhile. Each server can make their own moderation decisions. It puts moderation power back into the hands of independent admins instead of tech companies.
Personally I think this is only going to work for a little while but if ActivityPub catches on, it's going to be as inundated with spam as email is (without any of our modern spam filters). Therefore I personally moderate my ActivityPub server by whitelisting a handpicked list of servers that I personally trust (which I knew about by having browsed discussion groups on this topic).
As for the scaling question, there are two layers to that: per-server and overall-network scaling.
Per-server scaling doesn't matter. All that matters is serving content that the users of that server find worthwhile. Whitelisting works fine for this, but discovery requires checking out different servers or having out-of-band knowledge of other servers. I think this is fine. People can promote servers they find worthwhile in all kinds of ways, same way as for example gamers find gaming clans.
Overall-network scaling is a function of how all admins decide to federate. Right now most admins federate widely so the overall network has scaled very quickly. But really this doesn't matter either because there's actually not necessarily any such thing as an "overall network". If you made a graph of all ActivityPub servers in the world, there might be multiple disconnected graphs and that's fine. If admins in those graphs have decided not to federate with each other, that's the system working as intended.
> That's basically how things like substack work
My understanding (but correct me if I'm wrong) is Substack is a central server where multiple authors can publish their work. Federated content is different in that I can publish my content on my server and anyone who federates it can also get it on their server (and likewise I can get theirs on mine). But if I go off the rails then they can cut me out while still federating other authors they find worthwhile. Each server can make their own moderation decisions. It puts moderation power back into the hands of independent admins instead of tech companies.