KB Article: 56817
KB Category: [Account/Billing]
KB Sub-category: [Compromised SQEX ID]
Unauthorized access refers to a third party (someone other than the actual account user) accessing an account without permission and/or using information somehow obtained from the user). This is not only a violation of the Square Enix Account User Agreement, but may also be a criminal act in violation of the law.
Even if someone who has had an account accessed by a third party manages to take it back and successfully log in, it is not uncommon for items, gil, or even characters to be altered.