Baby Locks? What Baby Locks?

This picture is from a couple months ago but I thought it was funny. We have a child safety lock on the cabinet that contains our dvd player, DVR, etc. As you can see, it doesn't do much good. Both kids take it off like it is nothing and plays inside.
The funny part is what Caroline does when they are done playing inside. She closes the door, puts the lock back on, and says, "Daddy." She knows that I am diligent about keeping the lock on the door.