>perhaps moving it around (as would happen as you walked with it in your pocket).
One attack vector is stealing cars out of a supermarket parking lot. You just wait for someone to drive up in the model car of your choice and have your accomplice discreetly follow them into the store. When your accomplice texts you that they are at the bread aisle/back of the store you can just steal with impunity knowing that a bystander will see no difference between the actual owner who has the key in his pocket and you with your relay device in your pocket. You also know that your victim is in the back of the store and that they can't get within sight of you before you're already long gone.
One attack vector is stealing cars out of a supermarket parking lot. You just wait for someone to drive up in the model car of your choice and have your accomplice discreetly follow them into the store. When your accomplice texts you that they are at the bread aisle/back of the store you can just steal with impunity knowing that a bystander will see no difference between the actual owner who has the key in his pocket and you with your relay device in your pocket. You also know that your victim is in the back of the store and that they can't get within sight of you before you're already long gone.