Family maybe, but figuring out the real name from friends can get difficult.

I know a guy who has been using an alias on facebook for the past 8 years or so. It is funny to watch when his alias creeps in to real life. Normal scenario, Bob meets Alice, a friend of a friend, at a party. They friend each other on facebook, Bob uses the alias Claude. Sometime passes and they run into each other elsewhere. Since Alice met many people that day and now mostly only remembers Bob as Claude from facebook. Some confusion occurs when Bob's friends call him Bob while Alice is convinced his name is Claude.