I prefer IANALFAPP (I Am Not A Lawyer For All Practical Purposes)
I don't anal fapp, and really would not advertise it if I did!
When they have been "Proven to work" the scanners will be introduced at court houses. "But they are in use at the airport, so they are not an invasion of privacy."
Next you will see them in nightclubs. "Proven security technology, requirements of a licence, trust us not to keep the images.."
Schools? "But these are the same images as made in airports, so it is not indecent"
In space, no one can hear you fart.