That's not how it works though? They don't need to know "who you are," because with ads you have a unique identifying number. If you are browsing the web and your ads become more catered to you then you are giving data somewhere.

Privacy is about maintaining as little about yourself as personally possible. That is what gets me about this app. Half the users on here have very little idea how the Internet works. Privacy and security aren't about going, "I support open source and decentralized software so the big man doesn't have my data," but that is not how that works at all. Just because you aren't giving your data to Mark Zuckerberg and you don't support Facebook doesn't mean you aren't exposing your giving data to someone else.

I also truly don't think Lemmy users realize how exposed they are potentially making themselves. Even if the API is free and your app is open source and it isn't Elon Musk showing you your image of a cat does not mean you are private and secure.

Lemmy services and instances are hosted on a server and use an API that is open to anyone and everyone that wants to host an instance and community. So instead you are entrusting your data to someone you don't know on their hardware that you don't know anything about.

From a security and privacy point of view Lemmy is a nightmare. Mastadon, etc. Even if your data is encrypted or passed along secure channels and you can migrate your data to some other instances does not mean you are safe. That is not how the law works either. If a national government agency shows up and issues an order for their server data and that data isn't protected properly by the host well then you are exposed. The people acting like they know something more because you decided to pay for Sync or because you want to use Windows or Google literally no zero fucks about privacy and data.