You really aren’t as safe as you think you are. Look at Sneakey. From 200 yards it can read a key and copy it.
This is from the original paper.
In our telephoto experiments we captured Kwikset keys in an outdoor cafe near our department. In each experiment, we placed our target key, one of many on a ring, on a book resting on a cafe table. We mounted our camera roughly four feet above the ground oriented perpendicular to the key surface (rotations of the key out of the camera plane would strictly reduce decoding accuracy). For each of the ten keys we captured separate images at 35, 65 and 100 foot standoff distances. Figure 8 shows images of one such key at these distances, and provides a qualitative sense of how resolution degrades with distance. Manual focus also becomes more difficult, but this is not a problem at 100 feet.
Using Sneakey we decoded each of these keys with results shown in Table 2. These reults are highly robust and even at a distance of 100 feet, 7 out of 10 keys were precisely decoded within the first guess. All key shots taken at 100 feet were decoded within 3 guesses.
Finally, to explore the distance limits of our apparatus, we installed the camera on the roof of our four story department build- ing (77 feet above the ground) at an acute angle to the key on the cafe table — 195 feet away… produced the correct code within the first three guesses.
The moral of this story is you can never assume you are safe from prying eyes and bad guys. Keep your keys in your pocket. Don’t leave them lying around. They could be scanned and recreated on a 3-D printer. Make sure they don’t appear in photograph, Sneakey can work out their unique cut.