Every game, but Nintendo has banned people for it or I recall hearing that anyway.
The banning was more exclusive to those who opened multiple CN accounts to get more than one Gold / Platinum reward, not for having sub accounts on one main account. I legitimately registered my kids and wife, along with some siblings to fill out the additional 7 family member roster. All they really require is an email address, or for kids, you don't even need that to create a sub account.
- AFRO insomniac likes this