Google attempts to automatically blur faces, but the algorithm they use isn't perfect. I've noticed an image of Colonel Sanders on the store sign of a KFC that was blurred. I can't imagine that someone at Google manually went in to blur a black and white drawing of the Colonel.

On an interesting note, since the Colonel's image wasn't in color, looking just for flesh tones isn't required to trip Google's blurring. I guess Google wanted to make sure they'd even blur the faces of any mimes they came across...can't say I blame them for that one.