Who is Benedict Arnold?
Benedict Arnold was a no-good, dirty, rotten, traitor who deflected during the Revolutionary War.
Ooh... you mean here on answerMug? That's the account name that becomes associated with content when someone closes their account or gets deleted by an admin. Sure, we could just call them "deleted members" or "former members," but where's the fun in that?
If you'd like to read more about the traitor, feel free to browse the Wikipedia page about him: https://en.wikipedia.org/wiki/Benedict_Arnold