For whatever reason, a large number of the people I know go by names that are not their legal first name. Some go by their middle; some drop letters from their first name in idiosyncratic ways; some keep the same pronunciation but have a different spelling; some change the spelling while leaving the pronunciation and then drop letters; some go by irc nicks even in person; a rare few just invent words that have nothing to do with their names and go by that. Maybe it's a unique symptom of growing up in an era where we communicate via online systems that demand unique usernames?
Could be. If you've heard of someone primarily referred to by their online pseudonym, it may be less awkward calling them that than trying to guess at how they wish to be addressed using their real name. It's still awkward though.
