In the article ,"trouble with iPhone 5s's fingerprint reader " by Christina Bonnington explains how the iPhone 5 fingerprint scanning is have some malfunctioning problems. It is stated that if the home button is scuffed or damaged in anyway, then of course the program will not be working properly. It's because the home button is where you are putting you're fingerprint on so that it can read your print but once it is damaged it'll be difficult for the home button to read your fingerprint. The makers of the iPhone 5 S don't know why it's causing the trouble for people but they have suggested one of the causes. Anyways they've had to put these special materials in order for the home button to read the fingerprint clearly enough. In conclusion, if you are planning to buy the iPhone with the fingerprint scanner, then you have to make sure that you will not damage that home button.