Nostr (Notes and Other Stuff Transmitted by Relays) is designed to be a decentralized protocol for social networking. Here are some key points regarding private chats and privacy settings:

1. **Private Chats**: Nostr supports private messaging through end-to-end encryption. This means that messages are encrypted on the sender's device and can only be decrypted by the intended recipient. This ensures that even if the messages are intercepted by a third party, they cannot be read without the decryption key.

2. **Privacy Settings**: Since Nostr is a protocol rather than a single application, privacy settings can vary depending on the client you are using. However, some general privacy features you might find include:

- **Key Management**: Users typically manage their own public and private keys. The public key is used as an identifier, while the private key is used to sign messages and decrypt private communications.

- **Relay Selection**: Users can choose which relays (servers) to connect to. Some relays may have different privacy policies or levels of security.

- **Content Visibility**: Users can control who sees their posts by specifying the intended recipients or using encryption.

It's important to review the specific client application you are using for more detailed information on its privacy features and settings.