Some keys have bitting codes stamped right on them. Not a great thing but even if they don't, it's trivial to figure out if you have physical access to the key, or a picture of one. You can hand-file, or with a machine, create a reference key with all (or enough) bitting codes on it to compare for a particular type of lock/key system. Snapping a photograph of an important key is a pretty standard pen tester's trick that takes only seconds. Even without ever seeing your key, it's trivial to do key impressioning if the attacker has physical access to the lock. In situations where lockpicking is impossible because it would be obvious to observers, an attacker will come back repeatedly, and (starting with a blank one) jiggle a key in the lock to form impressions that can be used over time with repeated filings to create a working key for your lock.
Then there's the fact that most commercially sold locks are absolute rubbish, and easily picked by someone with only moderate skill in the craft. Failing that, an attacker will simply break a window to get inside or force the door. How strong is your door, and door frame? How strong is the glass in your windows?
If this software helps people to realize that keys need to be kept secret just like passwords, then it's done something positive, at least. If anyone wants to really understand physical security, they should take a look into the subject themselves. I recommend the books by Deviant Ollam, particularly Practical Lock Picking and Keys to the Kingdom. The latter book's final chapter "Don't Let Your Keys Talk to Strangers" specifically addresses the issue of photographing keys, among other tricks.
While you're at it, you should also try to learn something of digital encryption as well. The biggest security problems come from people blindly trusting in the products they've bought, without knowing how they actually work (or don't work), and using poor behaviors with regards to security. In other words, many people are clueless, and have no security at all, while under the unfortunate impression that they are completely secure.
