James, more than likely what has happened is that the user (we'll call him A) bought the account from someone else (B), changed the billing details and put on an authenticator. A could not change the secret question/answer as that is not changeable. B then later on decided he wanted the account back and put in a request for account recovery with Blizzard. Since B was able to provide not only the secret question/answer, as well as possibly the cd codes used during install, Blizzard had no choice but to lock the account until such time as it was determined who the correct user of the account is. I won't say "owner" because Blizzard in fact owns all accounts, we just lease use of them and access to the servers each month with our subscription fee.

So, remember kiddies - sharing accounts is BAD, and buying accounts is BAD. Even if you buy an account, or use a friends account because they are no longer playing, the original user of that account can AT ANY TIME put in a request to take control over that account again and *poof* all your hard work is gone.