Vissso usernames are only unique per instance on mastodon.
..
sooo.. thats gonna be interesting.
cuz you can just stand up your own instance, join it to the federated server and ... be someone else?
WAIT
CAN YOU NICK COLLIDE LIKE BACK ON IRC?!
Thracky Spackoid@Viss nope they get referenced as @user@someinstancedomain when they're on a remote instance