mastodon.online is one of the many independent Mastodon servers you can use to participate in the fediverse.
A newer server operated by the Mastodon gGmbH non-profit

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Edward Hasbrouck

@signalapp - I don't understand what threat model this is based on. Even if you use a username, your phone number will be shown to any other party to chat who already has that number in their contacts. But what if you don't want to reveal that the username you are using corresponds to a phone number they know? I want a user-selected handle that doesn't require a smartphone to create or use and isn't linked to any phone number.