We travel a lot with our little one (just turned one) and are going to be opting out of the body scan on our upcoming Thanksgiving trip.
First, I don't believe that security theater makes us safer, and I think this scan violates my right to bodily privacy. (So does a pat-down, but at least that person has to look me in the eye.)
Second, I am increasingly skeptical of the assurances that the amount of radiation you're exposed to by the machines is safe. Especially when operated by poorly-trained TSA people.
Third, I flat-out don't believe the claims that images will never be saved - the TSA has already gone back on that one. Now they can be saved for "training purposes and analysis".
Finally, we pretty much already do the patdown thing, and it's not THAT bad. We don't own a stroller, so our kid gets carried in wraps and slings, etc. Every time I travel (every. time.) I offer to take him out of the carrier, put the carrier through the X-ray machine, and just walk through the metal detector holding him in arms.
Every. Time. the TSA agent says no, they're going to have to:
*wand us both
*pat down my baby
*swab my hands for explosive residue
It's silly (my son, noted baby terrorist) and irritating, but I will absolutely still choose that over the untested, record-creating, privacy-violating nonsense of the bodyscan.