A bit of oddness on the capitalization side.
Logging in using possessedcow works perfectly. Logging in using POSSESSEDCOW does not. However, if I were to attempt to register the name POSSESSEDCOW, it would inform me that the username was taken. A similar issue occurs when I attempt to follow the feed of a user. possessedcow works, but POSSESSEDCOW does not. Since signup is case insensitive, it seems like a downcase on login/feeds would make logical sense.