Hello all,
Please read this thread,
Account Suspensions for Grey-Market Gold Transactions if you have questions about the process.
As far as seeing banned accounts, not all of them are for buying gold. There are a few reasons someone might show up as banned:
1. A glitch in the billing system.
2. A bug in the registration process
3. A disconnect between billing and subscription
4. In-game harrassment or a myriad of other things which violate the EULA.
If you have a pal with a question about being banned, they can fill out a support ticket. If they received an answer in a support ticket they do not understand or would like to dispute, they should simply respond to said ticket for research.