Anyone who has ever looked into the potency of metadata and data tracking knows how easy it is to extract people's behavior patterns and create intimate profiles of individuals from such data, and that without knowing the content. It even becomes more critical when payment transactions are added to the mix, which Nostr also has (Zaps aka Bitcoin Lightning payments). As every Nostr entity currently corresponds to one public key, all interactions can also be clearly assigned to an identity (= persons behind the PubKey). Accordingly, for a serious implementation of E2EE in a social network protocol, it is critically important to encrypt the metadata as well. 7/11