You are not the winner. you didn't even guess a number. We are talking in scenario's here. You are here (probably) because you want to win those accounts. since all your posts were made here.
you asked why you couldn't change the password or skin.
let me say it differently then:
You are not allowed to because these accounts are considered illegal to most. If you change them the owner of the account could notice. As soon as that happens he will most likely change his password causing You the one using the (illegal) account to lose it because the owner changed password
what would you do if you can't login to your bank account or something along those lines? You would most likely report it and find a way to get it back!