Who is that someone? The only one in my instance its me and no one else. My instance only download what its post , commented and upvoted on the instances I subscribed. My instance does not download what others are subscribed on other instances. For example if I am only subscribed to the Lemmy.ml instance I only get what others post on that instance , and if a user from lemmy.ml instance subscribe to a nefarious instance doesn’t mean my instance will get all those nefarious post because I am not federated with that nefarious instance.