This seems like it would be a more powerful argument if the fingerprint sensor on the iPhone was used for more things than unlocking your phone and making App Store and iTunes purchases. As it is now, Touch ID doesn't need to be technically more secure, dynamic, or anonymous than a passcode or password, it just needs to be faster and more convenient. And what does a perpetrator do once they've lifted your fingerprint and made a copy? They still have to steal your phone or gain access to it for some amount of time, which requires very personal targeting.