What kind of metadata? The Mac address is randomizedd on BLE connections and the nostr notes are signed. About location, every Samiz app will act as a relay for any note available on the local relay so the fact you received a note from device A doesn't means device A is the source, kind of like Tor and LN works. I'll take a deeper look to Briar anyways thanks 🙂. I already took a look before and as you said the goals are very similar, but Samiz is supposed to support the nostr protocol, which I believe has way more potential than an isolatend platform like Briar.