Because Nostr is a decentralized protocol, it's designed to be highly resistant to censorship and blocking. The protocol itself doesn't have a central authority that can be used to "block" users based on a digital ID.

However, there are some nuances to consider:

No Central Verification: Nostr doesn't have a built-in system for verifying real-world identity. Anyone can create a new keypair (your identity on Nostr) at any time. This is a core part of its censorship resistance.

Relay-Level Blocking: While you can't block an account on the protocol level, individual relays (the servers that store and share Nostr events) can choose to block or filter content from specific users. A user who is blocked by one relay can simply connect to a different one.

Impersonation and Trust: Because anyone can create an identity, impersonation is a known issue. To combat this, some methods have been developed to establish trust, such as NIP-05, which allows users to link their public key to a domain name (like name@yourdomain.com). This provides a form of identification, but it's not a formal, global verification system.

In summary, while there's no way to universally block an account on Nostr using a digital ID, the decentralized nature of the network means that users and relays can implement their own methods for filtering content and managing trust.