Don’t leave keys laying around. They could have their picture taken, and a new, functioning key can be made from the photo. Yes, using image analysis techniques called, for this purpose, Sneakey, keys can be duplicated from photos taken at a distance.
In one Sneakey demonstration, described here, keys were photographed from the roof of a four-story building, almost 200 feet away – picture a spy using the camera.
The whole key reproduction process uses software written in Matlab code. Watch out for it.