My second issue is specific to back-scatter technology. This is ionizing radiation, which inherently carries health risks. The risk may be low if the equipment is properly calibrated, but there is no way to know if it. (The backscatter machines are the ones that look like two giant blue refrigerators. There are also millimeter-wave scanners in use, which look like a large plexiglass box and the health risks do not apply to those, though, of course, the privacy concerns do.) I believe that either of these technologies amount to a virtual strip search and are inappropriate for primary screening. I do not have an issue with the use of millimeter wave scanners for secondary screening. They may be particularly useful for people with medical devices that will set off magnetometers, for example.
The pat-down procedure being used for those who opt-out or set off metal detectors or who are "randomly" selected (more about that in a minute) as it is currently practiced is also inappropriate, in my opinion. If the procedures being used to examine the genital regions were performed by anybody other than TSA (or a law enforcement officer under considerably more limited circumstances), they would be considered sexual battery.
As for random selection, my observation (admittedly anecdotal, but consistent with what others have reported) is that women are at least 3-4 times as likely to be selected. (I have read one TSA officer admit that he sends every woman wearing a skirt for scanning or pat-down. His logic is that if he can't see the outlines of somebody's body, that is supicious. That means that women who follow any religious practices that call for modesty are being particularly singled out. I believe some of the other reason for the disparity is that women are perceived as more likely to be docile and comply.) There are several problems with this. A simple one is that the scanners do detect sanitary napkins. Another significant issue is that there are fewer female TSA officers available, so that women often have considerable delays waiting for the pat-down. (Note that TSA promises only that they will attempt to have you patted down by an officer of the same gender, but does not guarantee this. I don't even have words for how offensive this is.)
There are several additional issues from the standpoint of safety (which is the argument for all of this. The pat-downs often add health risk as TSA officers do not change their gloves routinely, for example. A bigger issue is that more people will choose to use other forms of transit, all of which are more dangerous than air travel. Finally, people who have been traumatized by assaultive security procedures are more likely to explode with rage when confronted with additional stress.
My recommendations for dealing with all of this are:
1) Write to your congresscritters to oppose these practices. Specific points to make are health risks, violation of the 4th Amendment, and questions about undue influence by the companies that manufacture the technology.
2) Try to choose security check-points without the nude-o-scopes.
3) If you are asked to use a millimeter wave device, decide for yourself how you feel about the privacy issue. I am willing to use one of these instead of being fondled aggressively, but you may feel differently.
4) Opt-out of using backscatter devices due to the health risks. You will be patted-down. Insist the TSA agent change gloves, using fresh ones from the box, not ones from his or her pocket (which may have been used on another person previously). You must also insist on maintaining visual contact with your belongings while being inspected.
5) While you have a right to a private screening, I suggest that you insist on being screened in public unless you have a specific medical reason (e.g. an ostomy bag) not to. If you are screened in private, take your own witness. (You have a right to this. If they refuse to allow you your own witness, ask for a supervisor.)
6) Calling the TSA officers names or physically abusing them is rude and counterproductive. If you feel there are any questions about whether the procedures are being followed appropriately (a common one being the failure to tell you before touching some part of your body), gently remind them of that. You can also request a supervisor and, if necessary, elevate to a law enforcement officer. (The latter should rarely be needed.) There are also complaint forms you can fill out, in which case you should make every attempt to get the name of the officer whose behavior concerns you.