@polotek @anildash I think Marco is making a great point here, Anil.
There are so many other ActivityPub based services that already federate with Mastodon. And Mastodon’s norm is to federate by default and defederate from known bad. This is only a big fight to hate Threads or BlueSky but ignoring dozens of other services that are already doing this.
And even within Mastodon, defaulting to opt in only would destroy the federated timeline.
The norm here is to federate by default. It’s a social microblog posting service. If you want an opt-in only private service, Mastodon is not it. It’s not designed to be it, it’s not technically it, it’s not socially it.
It has a lot of solid visibility/follow tools and blocking tools to control how I see my feed. But it’s not for people who want active positive consent over how their posts are copied/used across the internet. It would need to be technically rebuilt from the ground up to be that and be a totally different product.