#[2]

Read-only access for non-paying users is too resource heavy. So locking it down where connection requires authenticating the npub with challenge in order to read would guarantee quality of service.

#[3]

But requiring the private key for reading from paid relays would break the simplest personal proxy server. These are desired as a way to substantially reduce the amount of data a mobile client needs to download by having your proxy sync from relays and filter on your behalf.

We could have the benefit of both pay-to-read and personal proxies after key delegation and revocation becomes a Nostr standard. We want this anyway to make it easier to keep our master private keys better protected, maybe even offline most of the time.