Depends on the protocol, and sometimes the situation, really. Maybe an example with Matrix? I have my own Matrix home server, it sits in my bedroom. I have a

Depends on the protocol, and sometimes the situation, really. Maybe an example with Matrix? I have my own Matrix home server, it sits in my bedroom. I have a friend with his own Matrix home server, and it sits in his living room. The chatrooms we are both in are synced to both of our home servers. If all users in the room are on my home server, all of the data is on my home server.