Yes. When you like or dislike something it gets synchronized with different federated servers. Which means, federated servers have a database of all your likes and dislikes, and even your posts. The server admins of that server have, by nature, the password for the database and can therefore track every move you make. Just one "Bad guy" that has a server that is federated with your accounts server and they will know a lot about you. And since its open source theoretically everyone can do this. Criminals, Stalkers, Governments, Companies, everyone.
But: Not what I liked or disliked. Every federated server can see that in their logs. Normally this would at least need you to talk to reddit/meta/some other company in order to get a hold of this data, but here literally everyone with basic Linux knowledge can get everyone's data very easy, very quick, and very reliable.
Yes. When you like or dislike something it gets synchronized with different federated servers. Which means, federated servers have a database of all your likes and dislikes, and even your posts. The server admins of that server have, by nature, the password for the database and can therefore track every move you make. Just one "Bad guy" that has a server that is federated with your accounts server and they will know a lot about you. And since its open source theoretically everyone can do this. Criminals, Stalkers, Governments, Companies, everyone.