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.
It's a good point. It's a weirdness that we have lived with, but could be addressed by downcasing without ramifications, I believe. This oddity is most problematic with shout-outs, which are currently case-sensitive. Hm. I am going to think on it, but very well may fix it. Thankfully we aren't in a situation with case-sensitive registrations.