No one said it's private. It's not commercial, there's a difference.

Depends on how you define private. It’s not “private” in the sense that it is accessible to the public interner. It is only more privacy-friendly in the sense that say, unlike Facebook, there is no need to use your IRL ID data, there are no weird algorithms baked in, and no targeted ads. Nothing would keep 3rd-party scrapers from profiling your posts that are public, but at least by default it’s not evil.

… until Meta will arrive on the fediverse…

The data you post isn’t more private like other commenters have mentioned.

On the other hand, lemmy and other open source social media platforms won’t collect behavioural data like other privately owned social networks.

Instagram for instance will track exactly how much time you spend looking at each post to determine your interests and predict which ads you are most likely to click on. Others than that they will also run experiments of changing some features and track your engagement with them.

So in essence, they collect more data on stuff that you don’t explicitly share.

Federated social media you mean? It's not. There are other forms of decentralisation which focus on privacy

It’s not, never was, and never claimed to be.

It's not more private. Who told you it was? What it is is more decentralised and interoperable, and thus more resistant to the bad decisions of individual instances.

Privacy and anonymity are two very different things. Meta et al very much tie your real world ID to your online persona plus track, analyse, store and sell everything you do on their platforms (and possibly what other sites and apps you use).

Your posts on Facebook can be set to "private" (only Meta and you/your friends see them), but they're never anonymous. Eg if you start saying unwanted stuff if you live under an oppressive government, you will have IRL trouble.

Your post on Fediverse can be public (everyone can see them), but anonymous (no-one can tie your IRL identity to your online persona). Eg you can make an account here and say things about your oppressive government and if you use basic anonymity tools (VPN-s, e-mail aliases etc) you cannot easily be tracked down.

You can also be private and anonymous, eg tipping off journalists about stuff going on under your oppressive government by using anonymous, E2E encrypted message service like Briar. That way no-one can eavesdrop on your comms and only you know your real identity.

it's not.

There is no one place to get everyone's private data (IP addresses, email addresses). It is of course still possible that someone may get that data from one instance, but that gives them data from only a small subset.

Private? Who told you this was private?

Is all the data public and shared tho? I don't think my instance is sharing any metadata, like IP, device, usage statistics and others? The metadata is where the value can be extracted to advertising use.

you'd have to encrypt your messages, and manage who has the keys for it to be private.

It's not private at all. In fact you can download everybody's private messages.

Any group/individual that runs a server can be approached by, say Cambridge Analytica, just the same way Zuck or one of his C suite execs were.