from: http://www.n-europe.com/news.php?nid=11842
"Nintendo won’t allow Miis by the name of Hitler on its Wi-Fi service.
Let’s be honest, if you’ve got a Wii then chances are you’ve created Miis of people other than yourself. Forget that failed attempt at recreating Bowser, we’re talking about famous people – if you haven’t at some point tried to create Hitler then you, friend, are in a minority. It seems Nintendo has latched on to this in its ‘safe and fun’ policy by banning Miis with the name Hitler from Mario Kart Wii.
People who select their Hitler Mii and connect to the Wi-Fi service will be kicked back out again with the message ‘You cannot access Nintendo Wi-Fi Connection using this Mii name. Please change your Mii name and try again’. What happens if you share the Nazi leader’s name? Blame Nintendo, not us!"
I had to laugh when I read this because I too have made a Hitler Mii...
Apparently it's been like this since Mario Strikers, but this is the first time I heard about it. And apparently you can get around it by using a capital i for the L...