The scanner in question was not used for air travel. Perhaps even more ironic, it was in a courthouse. Gizmodo took a cue from an EPIC lawsuit (PDF of complaint to the US DoJ) and filed a Freedom of Information Act (FOIA) request for 35,000 images saved by this one scanner under odd circumstances.
Their report shows quite clearly how hard it will be to trust anyone running these systems; it is called "One Hundred Naked Citizens: One Hundred Leaked Body Scans"
A Gizmodo investigation has revealed 100 of the photographs saved by the Gen 2 millimeter wave scanner from Brijot Imaging Systems, Inc., obtained by a FOIA request after it was recently revealed that U.S. Marshals operating the machine in the Orlando, Florida courthouse had improperly-perhaps illegally-saved images of the scans of public servants and private citizens.
Reminds me of when I worked many years ago to protect Radiology images and detect leaks by staff. Anyone working in health care should hold the safety and welfare of the patient in highest regard, and yet there is a nearly constant risk of breaches and leaks to the media. The celebrity, Farah Fawcet and Octomom etc., cases may be the most known but there are many many others. Any image that was remotely interesting (imagine things swallowed, for example) quickly became a very high-value asset. You know what will happen when a professional sees something really interesting or funny and wants to show just one really close friend…and so information security again becomes the key to whether a product can survive.
I stopped going through body scanners a couple months ago and so far so good. It has actually been without incident. Then again, I was not trying to taunt TSA staff and see how they can handle passenger resistance.