Kevin Kelly writes about software created by Dmitri Bitouk and Neeraj Kumar of Columbia University that "de-indentifies" people in photos to protect their privacy.
Face swapping software finds faces in a photograph and swaps the features in the target face from a library of faces. This can be used to "de-identify" faces that appear in public, such as the faces of people caught by the cameras of Google Street View. So instead of simply blurring the face, the software can substitute random features taken from say Flickr's pool of faces. A mouth here, an eye there.
Face Swapper Privacy (Conceptual Trends and Current Topics)