Respectfully, I disagree.
1. You can screen your doctor for trustworthiness.
2. You can choose to visit a doctor of a gender you prefer.
3. Doctors are bound by the Hippocratic Oath: I will respect the privacy of my patients, for their problems are not disclosed to me that the world may know.
4. Doctors rarely take, much less retain, nude photographs of your body.
Collection and use of personal information, including digital photographs, paves a road for government with inscrutable purposes: using information about people while denying them the ability to choose how that information is used. This is a severe tilt in balance between the power of the people and the power of the state. A tilt, to emphasize, that is unfavourable to the people.
In Smith v. City of Artesia, 1989, the court said, "Privacy is inherently personal. The right to privacy recognises the sovereignty of the individual." What is more private than our private parts? What can the general public be subjected to, en masse, that is more personally invasive than a pat-down or nude photo?
More blunt? Can do.
The choice: allow an anonymous agent to take nude photographs of your child, or let strangers grope your child until their hands meet "resistance": a euphemistic way to say, "touch their testicles, penis, or vulva."
Any job that forces someone to feel a child's crotch so as to encourage parents to usher their children through a machine that takes nude photographs--without probable cause of having committed a crime--is a job that aught not to exist.
Systematic violations of our private areas must be countered with outrage and utmost resistance (!) against corporations and governments alike. The TSA are not police and North America has no Police States, yet.
Add to this the uncertain health risks. Terahertz waves have resonant effects that can unzip double-stranded DNA, which, ultimately, could significantly interfere with gene expression and DNA replication. Think children, pregnant women, or sperm. And guess what wave frequency x-ray backscatter machines use? Hint: THz. http://arxiv.org/abs/0910.5294
My emotions surge at the thought of people speaking or acting out against tyranny. People must express themselves vehemently and eloquently against the infractions that governments permit to be made on our freedoms. Sometimes one voice, or one courageous action, is enough to inspire a nation. http://i.imgur.com/cfifB.jpg
Martin Niemöller foretells of what happens when people--even those who prefer to drive than fly--keep quiet: They came first for the Communists, and I didn't speak up because I wasn't a Communist. Then they came for the trade unionists, and I didn't speak up because I wasn't a trade unionist. Then they came for the Jews, and I didn't speak up because I wasn't a Jew. Then they came for me and by that time no one was left to speak up.
John Dewey stated, "We cannot separate the idea of ourselves and our own good from our idea of others and of their good." When we protect the rights of individuals by forcing Corporations and Governments to sit at the same table as Respect, Dignity, and Decency, we protect all of our society.
I implore you to read: http://davidjarvis.ca/dave/letters/nothing-to-hide.pdf