As a followup on the previous post http://cegamers.com/cegamers/gamers-protect-your-accounts/

If you have stored payment information on Facebook to simplify transactions, persons with access to your account can purchase items on Facebook, such as Zynga game cash (Farm Cash, Reward Points, etc), using Facebook Credits.

The actual purchase of Facebook Credits redeemed for Zynga game cash is processed by Facebook and not by Zynga, thus Zynga does not have the ability to remove any information stored on your Facebook profile.

To remove the payment information stored on your Facebook profile, do the following:

1. In Facebook, click Account at the top right corner of the screen and select Credits Balance from the drop-down list.
2. By Payment Methods, click manage.
3. Enter your Facebook password at the prompt and click Continue.
4. Click Remove next to the payment method you would like removed from your profile.

These steps will remove your payment information; however, Facebook will automatically store this information again upon your next successful purchase.

If you have further questions surrounding this policy, please contact Facebook here.