It’s the sort of thing you see in a Jason Bourne movie. A security camera watching over a crowded space snaps a picture of someone. A few seconds later, a supercomputer churns through a database and returns the person’s identity. The CIA knows all.
 That same technology is now, for better or worse, available to anyone with a smartphone. Earlier this year, a couple of Russian programmers released an app called FindFace. It lets people take pictures of complete strangers and then almost instantly find them on social networks. See a pretty girl or guy on the street? Snap a pic, get to know them. What could go wrong?