Your username is attached to all your edits when you're logged in to this wiki and throughout all of wikia.com. This is partly for accountability reasons, but it's also helpful from a copyright perspective; if someone wants to use your contributions in a way not allowed under the Creative Commons Attribution-Share Alike License 3.0 (Unported) (CC-BY-SA) they can ask on your talk page. This also encourages people to give the appropriate credit to authors and your username is used to give that credit.