Then the person who can sign a message from the earlier address can still get it back, but it isn't ever going to be a foolproof system. Hopefully people won't need to do this with the 2-factor auth on the new forum.
theymos has said that he will investigate any claim of a hacked account thoroughly enough so that he will not recover an account based on a signed message only. If there is evidence that the account was sold then he seems to not recover an account. That's the way to do it but I can see theymos not recovering many accounts because that would be a awfully long process I can't wait for the new forum software so we can rest a little easier with 2 factor authentication. Hopefully we'll have a phone + email choice. I don't get on with google authentication very well.
