Needing an invite to join, the apps, etc. all gives a certain sense of privacy over on Blueskye. But that’s just show. The API that powers the app is publicly available, no authentication needed. Every post made on Bluesky can be queried publicly by everyone, even without having an invite.
Mario Zechner has demonstrated this well with his low-effort (but amazing!) tool Skyview (source-code available on Github).
It’s a pure client-side web application that requires the link to a Bluesky posting as input and then renders the entire discussion thread around it. Pure client-side, no server, no authentication. Amazing!
That’s not a problem in itself, but just keep it in mind.