It's a camera taking a picture, of course it can be defeated. It's a good thing the fingerprint scanner isn't... wait. These things are toys. If you expect meaningful security from any of them, you've been fooled by marketing.
Touch ID is a capacitive fingerprint sensor embedded behind a sapphire crystal cover. The sensor works by forming a capacitor with your finger/thumb. The sensor applies a voltage to one plate of a capacitor, using your finger as the other plate. The resulting electric field between your dermis (layer right below your outward facing skin) and the Touch ID sensor maps out the ridges and valleys of your fingerprint.
http://www.citeworld.com/security/22399/iphone-fingerprint-s...
(Though it may work for a very short period of time if you were alive when they cut it off, but not for long)
They're so cheap to manufacture that you can sell them for $1 and still make a profit.
http://www.alibaba.com/product-gs/325177895/High_Performance...
That's exactly the point. It doesn't matter whether it's really hi-tech or unique or not. It's Apple's ability to present these things in a way which just makes you salivate that matters. This is a point which seems so hard for tech people to understand... it doesn't matter if you think people should see through Apple's claims, the spoils go to Apple because they know, as seemingly no other company on earth does, how to entrance people. A few key features, lavish, presentation, a feeling of luxury... that's what builds anticipation and excitement. Apple's closest equivalent are food companies, who have mastered the dramatic, salivatory description of products.
This ad campaign illustrates the point.
http://scoopertino.com/apple-blasts-into-supermarkets-with-r...
The only thing that is relevant is whether it works. Everything else is irrelevant.