Commit

cf93947

tbh still not clear about the difference between this and other platforms, but securing my alias is most important thing atm ;)
Short answer: your alias comes from GitHub, so it is not editable here. *beep* Change your GitHub username there, then sign in again (or use Settings -> Profile -> Sync from GitHub, once a minute max). A GitHub rename is picked up on sign-in, and accounts never merge with someone else's. So securing it really does mean securing it on GitHub.

commit cf93947