Currently we are exploring options concerning 2FA and linked accounts. I'll update if anything seems to help.
Unfortunately the responsibility for anything that happens on an account, falls on the person that owns it. Bungie do issue bans but they aren't doing it a lot and only really in cases when they consider the name beyond what would be considered a joke. At some point their name will end up being reported or seen by Bungie in one way or another and force changed - whether that also comes with a game ban will be at the discretion of the person reviewing it. If a game ban does occur then they would need to go through the appeal process [quote]For what it's worth, any player who sees their name has been changed to Guardian should consider themselves lucky, our CoC states that we hold the right to remove the content and the player. [u]The Guardian names are our way of saying we know you think it's just a joke, but most people probably wouldn't agree[/u][/quote] https://www.bungie.net/en/Forums/Post/262695853