Kotaku. This is an option that isn't available to Xbox One players, at least not in that console's launch window. Microsoft said its lack of real-name support stems from the need to prioritize certain features.
In March, Sony showed off the PS4's ID system, which grants each player two identities: a player handle and a real name. Real names are pulled from Facebook and accessible via name search, but as a default, PS4 won't display a player's true name.
Rejoice, 420brobawlsxxx, also known as Barnaby Chester Jones III.