The idea is not to have to talk with everyone in the circle, but to have enough people to create a long tail of niche interests.

Wait, what? Can a Lemmy instance have a /c/foo and /u/foo at the same time?

We could have a constellation of smaller service providers, like we do for email nowadays. Everyone talks about Gmail+Outlook having 80% of the market, but we all forget that the tail still exists and that is made of hundreds of independent companies which make a healthy living charging $20-$50/year.

How about we get some things out of LW a bit? There is a whole instance for football at soccer.forum, waiting for more people to join in.

Sounds like something that could be useful for Lemmy itself, no?

The "problems" I am trying to solve are a bit like bug #1 on Ubuntu's Issue tracker:

• I don't want to have an Internet which is accessible to large majority of people through "platforms" controlled by large corporations.
• Surveillance Capitalism is a net negative for society. People should be able to access services without having to give up their privacy.
• The attention-based economy has caused terrible damages to civil debate, media institutions are no longer focused on factual reporting and depend on polarization, emotional manipulation of issues and only report on things that are favorable or inoffensive to the Status Quo.
• Because of increased automation, knowledge workers will be increasingly pushed out of meaningful and well-paying jobs and will be forced to try to monetize every aspect of their life. There are no more hobbies, everything is a "hustle" or a "side project".

I hoped that all the things that I've worked on with Communick were made to the sense of mitigating these problems.

• Provide open source platforms which can be self-hosted, but do not demand users to become part-time admins.
• Instead of ad-based revenue, make a honest value proposition: I offer a service, people pay to use it.
• Create a system where people can allocate a budget to support artists and free/libre developers, to foment a reconstruction of a more open culture.

That's is not the right analogy. No one is making the bridge and saying "I can take the content from person A on Lemmy and sell it on Bluesky". they are just saying "Here is a copy of what Person A posted on Lemmy".

In terms of copyright, why is it okay from someone on a different Mastodon server to relay content from a Lemmy server and even redistribute it (through, e.g, RSS readers), but it's not okay for a bridge to redistribute it to a Bluesky server?

No. There is a difference in context and intent.

Bottom line is, if people are concerned of having their conversation and content distributed out of their intended audiences, we'll all have to move to a fully encrypted network, where every message can only be decoded by the intended recipients. Getting upset because other people are not agreeing to your expectations of privacy is pointless.

How does 2 way mirroring work?

That will depend on a few things:

• If it's an user that has "converted" via alien.top's portal, we can work as a real reddit client and send message on behalf of the user.
• If the lemmy user is not on alien.top but wants to enable a two-way bridge, then we will have to do an authentication dance and send messages with passcodes to both reddit and lemmy.
• If the user does not want a bridge, we can still send a message to the reddit thread via another bot.

The last one would be the easiest to implement, but I'm avoiding releasing this because it might be taken down due to spam.

What about "privacy" is being violated when every post and submission is public and indexable by any search engine?

This can (should?) be resolved by the client application. There is nothing stopping us from developing one single frontend that can pull data from different instances and shows it in an uniform way.

The key part is this:

it turns out protocols really are just a formalization of Python's duck typing.

Meaning, this is just a way to say that if you are defining some system that needs to conform with some interface, you can have type checked even if your have different objects from different classes. No need for TypeVar or define a crazy hierarchy: as long as the types implements the methods defined by the Protocol, the type checker will be happy.