I suggest, before reading this, that you read the prior article I wrote explaining what Nostr is and how it works at a high level. You should then have a good idea of the core design of the system at that point, so now let's take a look at likely problems that are going to occur as it grows in adoption. With the platform becoming a popular one for the Bitcoin community, these problems are ones to be aware of.

As I discussed in the prior article, user public/private key pairs are integral to how Nostr works as a protocol. There are no usernames, or any type of identifiers that a relay server is in control of, to associate to individual users. It is simply those users' keys that are completely under their control.

This functions as a tight binding between the actual user and how they are identified by others that prevents any relay server from unbinding those two things, i.e., giving someone's identifier to another user. This solves one of the biggest fundamental problems of platforms used for communication between people: the lack of control over users’ own identities. But it also introduces all of the problems of key management that someone possessing a private key runs into. Keys can be lost and keys can be compromised and if such an event were to occur, users have no one to go to for assistance, just like with Bitcoin. There is no customer support to recover anything. You lose it, that's it.