Some of you have probably heard of bump keys. They are keys that will fit into a lock and when they are hit with a hammer or hard object the lock opens. There are numerous youtube videos about it. I saw a clip of a news anchor that went to a bunch of different houses with different locks and asked the owners if he could try it. He was able to open every single door. It was kinda funny because the one time they filmed him doing the entire process on camera he had to keep trying it, but in the locksmith it worked easeir and the homeowner managed to use the bump key and open the door the first time. These keys are filed down to the lowest point all the way across the part with the teeth. Anyone can make them, and they are easy to buy online. As long as the key is the right blank for the lock the bump key will work. This leaves NO SIGNS on the lock that it has been opened!!! They have been around for years and are becoming very popular again. Many states do not have laws specifically saying that bump keys are illegal. However, they are usually considered burglary tools unless the person who has them is a licensed locksmith. I know that PatriotGirl's daughter got into her home when it was locked and they didn't know how. This could be one way. It also could happen to any of us, and difficult children who are prone to burglary could easily learn about this so any of us could have a problem. I hope none of us ever has a problem with this, but I wanted to put the info out there. When you are at home it is a very good idea to use a chain lock or other lock in addition to the regular lock. Here is a list of bump key videos on youtube: http://www.youtube.com/results?search_query=bump+key&aq=0 Forewarned is fore-armed, I hope!