"The warrant is supposed to be delivered by someone representing the Justice department, which is (theoretically) independent from the police."
I hate to break it to you, but the FBI is part of the Department of Justice. I think you mean that a warrant needs to be issued by the judiciary, which (as far as I know) is a truism. Courts issue warrants, there is a warrant in the Apple case, and it in no way involves a "backdoor" being placed in all Apple phones.
You really might want to look up some of the facts about this case. It's not nearly as general as you think it is.
I hate to break it to you, but the FBI is part of the Department of Justice. I think you mean that a warrant needs to be issued by the judiciary, which (as far as I know) is a truism. Courts issue warrants, there is a warrant in the Apple case, and it in no way involves a "backdoor" being placed in all Apple phones.
You really might want to look up some of the facts about this case. It's not nearly as general as you think it is.