If you have the time
Apple does publish the security model for iOS 9 and later. It makes interesting technical reading and if you truly want to understand the security model that everyone is discussing, its worth the time.
<http://www.apple.com/business/docs/iOS_Security_Guide.pdf>
Here's another from 2014: <https://www.apple.com/br/privacy/docs/iOS_Security_Guide_Oct_2014.pdf>
Please read them, or any of the other explanations available here or through a quick search, before posting what is or is not possible for Apple or the FBI to do in this case. It will save you looking a little foolish on the internet, and the rest of us from having a heart attack over having to explain the situation for the nth time.
I have gotten to the point I've printed the document and just hand it to people at the office who start in the whole subject.
Biting the hand that feeds IT
