If your device is stupid enough to order things when some random person on TV tells it to, then your device probably shouldn't be in people's homes.
Hell, it should also pay its customers for the hassle of finding themselves drafted into being beta testers.
Last night my wife and I spent about half an hour talking and SIRI activated twice--neither of us said anything to her and she doesn't even understand my wife's accented English very well. Casual voice recognition simply isn't up to the reliability to do automatic orders yet.