Steering locking up

I have a question, is it normal for the steering wheel to be locking up by itself when I take out the key? I know it is supposed to do it when I take the key out and turn the wheel until it locks, but lately I have noticed that even if I don't lock it, when I get into the car it is locked and the key is free-spinning until I unlock it, it does it sometimes but I'm not sure if it's normal or if may be something is wrong with the ignition mechanism and one day I will just get into the car and the key will just keep spinning!!!