Can we agree that Apple should not be marketing this as a "highly secure way to access your phone"?
TouchID is highly secure if the only way to break into it is to have an ultra high-def image of the exact finger the device is looking for. I guess 50 character-long passcodes aren't secure because you could just tell a thief the code?
We must have wildly different definitions of "highly". I'm pretty confident I could reproduce this result in one afternoon. Compare that to other things we might consider highly secure, like strong encryption or Fort Knox. What word do you use for security measures that take non-trivial resources to circumvent?
How do you approach that part of the problem?
But if I were trying to break into an iPhone, perhaps the finger prints are on the phone. Or some other item I also got as part of the same theft. Or I found the phone in the owner's house when I robbed it and have my pick of surfaces. Or I have the owner's prints in a database because they went were convicted of a crime(I admit I have no idea what resolution those are taken at). I don't think there's a shortage possibilities. You leave prints on almost everything you touch.
To be extra clear, I'm not saying the finger print reader isn't good enough for most iPhone users; I'm not arguing the nth-grandparent's point about that. My point is that it's not highly secure, and Apple shouldn't be marketing it that way. Similarly, the lock on my front door is plenty good for my house, but no one would ever describe my house as highly secure.
You do have a very valid argument.
It needs a 2400 dpi output. This is not hard. 300 ppi source can easily generate a 2400 dpi output. DPI =/= PPI.