My wife and I opted out every time we traveled. From what we've researched there are two basic versions of those things and one is questionable as far as exposure to harmful rays and the other is a question mark. No thanks. We opted out and made them get a male and female TSA agent to manually search us... IE, free grope. I was amazed at how many people were fine with going through those things in the name of saving time or going along to get along or doing what they're told or whatever. In a little way I feel like we did our part to make things just that much more difficult on the TSA which may or may not have helped. Glad they came to their sense and now we just need to work on the rest of the TSA BS they're cramming down our throats.