Some places *do* use metal detectors. Besides most local state buildings and the county courthouse, I've set off detectors in a museum and several businesses. Oh, and the usual hassle at airports, before I gave up on those.
I have a steel rod in one leg, courtesy of a crackhead driver. The rod has caused much "security" excitement over the years.
My watch and eyeglasses (which say they're titanium, but who really knows?) have caused detectors to freak out. So has my wife's bridgework. Much puffing and posturing mall-ninja attitude when she refused to take her teeth out so they could inspect them.
Any more, if the detectors go off I just keep walking. Maybe one time out of five or six, someone will ask me to stop. If they're polite, I will.