Authenticator owners received a nice surprise in their mailboxes when Patch 3.3 dropped: the corehound pup pet. It's absolutely adorable and a completely unexpected bonus to having a secure account. But it has also caused much kvetching among those who feel they are too careful to ever need the authenticator. Pet envy caused some to sign up for the free application for their phone or buy the physical gadget in order to obtain the two-headed cutie. But they soon discovered that removing the authenticator from their accounts also removed the pet.
Their loss can be your gain, however. One problem that many guilds have is that some of their high ranking members, with full bank access, have account security issues. When a guildbank gets raided by a hacker, it affects the entire guild -- not just the compromised account. One thing guild leaders can do to protect all members is require authenticators for bank access. Previous to patch 3.3, this was hard to prove. Now GLs can just ask to see your corehound pup.
Of course, players can get the authenticator, show the pup and then deactivate the added security right after. So spot checks (perhaps at the beginning of every raid?) would have to be performed periodically. But this is a very easy way to ensure the security of a resource that affects an entire guild. At the very least, GLs can require that members previously hacked show their pets.
I know I'm not the first to think of this and I'm sure that some guilds have already put this into place. I think the biggest obstacle guild leaders will face is the group of players who feel their account is completely safe without the authenticator. It is a slight inconvenience in that you must have the gadget/app near you whenever want to play. However, just like an extra lock on your front door, an extra layer of security isn't going to hurt anyone but wannabe hackers.
Here is a handy FAQ about Authenticators, should you or someone in your guild still be on the fence about getting one. And don't be surprised if your guild bank becomes restricted to corehound pet owners after the next time a guildie gets hacked.