If you have a regular account ban that was not caused by an associated account, please see this page instead.
The reason that you are banned because of an associated account is because you have either shared your account with another user, or they have shared their account with you. If their account gets banned, all accounts on the device will be banned as well to prevent ban evasion.
To prevent this from happening in the future, do not share account details with any other user and do not log in using someone else's credentials on your devices. If your account details have been used to log into a device that you do not own, please use this link to change your password. Then, use this link to sign out of all devices. Besides running the risk of associated bans, you are running the risk of getting your account stolen. Do not share accounts with other users as this is against our Terms of Service and Code of Conduct.
If you have been banned because of a "Related account" as noted by the ban reason, please send us a ticket here.