Hello,

We can unlink your Yubikey for now but we will need to give your account AML status. You will have limited access to your account, but you will be able to login and trade. If you could either mail back the broken Yubikey to us, we will lift the AML flag and mail you a replacement Yubikey through EMS for free. Please be aware that you do not need to mail the Yubikey through any express services since normal mail should get here without any trouble or high expense. If you are unable to mail the Yubikey, please go through our verification process to lift the AML flag https://mtgox.com/forms/verification

We sincerely apologize for the issue you are having and would appreciate your cooperation through this matter.