A bit of Mastodon fun: I can now be simultaneously found via the alias "@ [email protected]".
That username is entirely interchangeable with my real @ [email protected] username. You can mention it and I will receive the mention, and you can search for it to find my account.
Here's a mention using the alias: @alex.
And here's one using the real username: @alex.
In practice, these appear identical! The Webfinger protocol is cool. (You don't need to self host to do this.)