I can predict these kinds of problems with biometric security. In the race to be the first to implement, Apple may have made a terrible mistake for a lot of people. I would now avoid these phones.
What's to stop them from mutilating you until you reveal your pin?
It's easier to quickly slice off the fingertip, no questions asked. Phone theft is so widespread and sophisticated you can expect new tech developed for quickly extracting fingertips coming soon.