Carrousel7956 Nostr and ActivityPub are not social media platforms; Mastodon, Bluesky, and Damus is. Check contact (grapheneos.org) for a list of all platforms they officially appear on.
The security@grapheneos.org address is for reporting high priority security issues related to GrapheneOS. [...] a much lower priority if you misuse this address.
The official X account for the project is @GrapheneOS which is used for official announcements.
The official Mastodon account for the project is @GrapheneOS@grapheneos.social which is used for official announcements.
The official Bluesky account for the project is @grapheneos.org which is used for official announcements.
Hiring [...]
No mention of a Nostr public key, indicating any "GrapheneOS" user on Nostr protocol is a mirror at best.