When I look at an "app" (1) like Face Stealer from Yahoo Japan, I wonder what it is the author's were thinking? If the author's were alienated teenagers writing a program to prototype looks for a horror film, then the app is a work of genius.
But if the authors thought they were merely doing something cool, or neat, then it is the app itself that is horrifying, as is their lack of awareness of impact of the results.
Faces are more than they appear. We have a lot of perceptual machinery to perceive and interpret faces, and it is easy to go wrong. This app supposedly maps another face from an image onto your face in real time.
The Internet is, among other things, a cabinet of perverse curiosities and Face Stealer certainly deserves to be collected.