So, a malicious entity can poison the petnames that others see, but only if prefixed by their own first? So people will learn not to trust them, I guess… but as usual with trust, they can be 99% correct and poison a specific one (eg claim a certain number is a well-known rich guy, and impersonate them)

The bigger issue is that people will need to be careful not to give embarrassing or compromising nicknames to people in their addressbooks.

I had considered using these personal contact list display names as default names for when people accept invites, but the problem is that they’ll know the inviting user had them as “that crazy pooky bob”