I formerly flew for a living and got patted down atleast once or twice a week because I won't use the Rapidscan 1000 which is installed at Phoenix Airport. I have no idea whether 10 uRems of ionizing radiation is bad for me, but all the Rapidscan techs all wear radiation dosimeters. Clearly, someone is concerned. Alas, I get enough radiation as is - so why risk it? I don't have the same concerns about the Thz non-ionizing radiation units made by L3. However, I don't have that job anymore and won't get on an airplane unless someone is paying me!
These scanners are worthless though. I am an American citizen with provable birth record, gun licenses, completed KnownTraveler screening, and my strong dislike of Muslim fundamentalism is far from hidden. I am a member of multiple frequent flier programs and if I haven't tried to blow something up in 7 years, why would I start now? Could I go through the metal scanner instead? No. However, the black muslim immigrant in head scarf who works at the Starbucks is allowed to.
Who do you think is more likely to be a threat? According to the brain trust at the TSA, me.
How long before Al Qaeda has people terrorists board with Ebola or Hemoraggic Fever or some other horrendous disease that you can't treat? As long as we're focused on "things", we're doomed. Terrorists have proven to be smarter than the US government at every turn.
Besides, couldn't the terrorist just stick it up their ass and get through anyway? Our government should send the scanners to the same destination.