Stuff stolen from your car

Way back when I had an 8 track quadraphonic system and had 3 of the 4 speakers stolen. A few years later, I came home from the grocery store with 4 bags of food. I carrried two into the house and by the time I got back out to the car, someone had taken the other two! Wasn't even a 30 second window of opertunity there! Crooks will steal anything.....even if they don't need it. I've had an unlocked padlock taken off my gate. Now without a key, what good it that?