Back when our @#$%! Blazer was less than a month old, we had parked it at night in a back parking lot at an inner city high school (in Des Moines!!!) while conducting a seminar inside the bulding, and some kind people had discovered a bunch of teens unscrewing the last of our lug nuts-- they had already removed ALL the nuts on the other three wheels. The people had caught the kids red-handed and they ran off, but we ended up having to tow the Blazer on a flatbed to a dealer because all but one of the lug nuts were gone. Probably in one of the kids' pockets. They were obviously going to yank the tires after they got all the nuts off. Had we tried to drive the vehicle, it would NOT have been a good thing, needless to say! We did have the dealer install wheel locks the next day, just to protect those big Michelins. Granted, a pro could have gotten around the locks, but as others have mentioned, it's another deterrent, as so many kinds of locks are.