Correct. You have access controls to your POD thus the data within it. As long as there’s an app built for a platform compatible with the protocols ActivityPods is compatible with, which are currently ActivityPub and Solid protocols it will work. It’s not just microblogging and not only compatible with Mastodon. So you can host your POD which would be best or even use a provider which you still have access controls. It’s like renting a locker or storage pod