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.
The fingerprint sensor is not an optical device. It's a capacitive device, so it will take a bit more to fool than a photo. See page 8 of the review:
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.
The fingerprint scanner uses RF to look at the layer of cells below the outermost layer of dead cells, so it's doing far more than taking a photo. (That's been covered in recent days on HN)
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.
http://www.androidpolice.com/2012/08/03/android-jelly-beans-...