We’re all pretty familiar with the iMessage bug that let iMessages get through on stolen (or new) handsets and how to fix the problem. We all suspected that this problem was fixed with iOS 6, but didn’t have confirmation until now.
From Apple via TNW, it’s been confirmed that if you change your Apple ID/iTunes password, all other devices using iMessage will have to enter the password to use iMessage, plus getting a new SIM or wiping your iPhone with Find My iPhone will also reset things:
This means that, if your phone is stolen, you can change your Apple ID password and all of your devices will require that password to be re-entered before anyone can use iMessage on it.
In addition, placing your SIM in a new phone with the same number associated or wiping your phone with Find My iPhone will now disable your stolen device from receiving iMessages. Both of those were common fixes that appeared not to work for many customers under iOS 5.
From: The Next Web
This is great not only if you lose your iPhone or it’s stolen, but also if you’re selling or handing your iPhone down to someone else. About time not only that it’s fixed, but it looks like we have real confirmation that the fix is for real this time.