Currently, a user can simply post an `about` message in the stream. Clients will then automatically use this name instead of the key.

What happens if two users post an about message with the same name?

what happens "in real life" when two people go by the same name?

Scuttlebutt works the same way: anyone can name themselves anything and anyone can name other people anything, it's up to the client how to interpret those messages. more on how SSB embraces subjectivity: https://youtu.be/P5K18XssVBg.