Genuine question, I don't actually know the details: how does the contemporary notion of avatars and usernames to distinguish identity or alter-ego interact wit

Genuine question, I don't actually know the details: how does the contemporary notion of avatars and usernames to distinguish identity or alter-ego interact with the notion of what a legal entity is? If I practice security hygiene across multiple identities online and only do certain things using certain representations/usernames... how would it work out in practice if I tried to argue that each representation was a distinct and separate entity of agency? Hmm. Thinking about this I now realize that identity fraud would probably be a lot harder to pin down if things leaned in the direction I'm describing, so perhaps not.