No, you may not put your hands in my pants

From KMOV 4 in St. Louis. Even if you are okay with the X-ray backscatter devices, you're not safe from the groping:

Business traveler, Penny Moroney, was flying home from St. Louis to Chicago. Like all other airline passengers, she had to go through security first. When the metal in her artificial knees set off the detectors, she had to undergo more screening. When Moroney asked if she could go through a body scanner, she was told none were available.

Moroney explains “Her gloved hands touched my breasts...went between them. Then she went into the top of my slacks, inserted her hands between my underwear and my skin... then put her hands up on outside of slacks, and patted my genitals.”

Why are there so many people that think this kind of screening is acceptable in order to board a plane? Why are people so afraid that everyone around them is a terrorist just waiting for an opportunity to kill them? Why do so many people say things like, "Anything that makes the plane safer is OK with me."? Yet these same people will happily walk into a grocery store, or mall, or church without any fear of the supposed terrorist threat. Do they really believe that terrorists only blow up planes and if no planes are available they'll simply stay home and take a nap?

The ability to travel is a Constitutionally guaranteed right. From Wikipedia's article on Freedom of Movement:

As far back as the circuit court ruling in Corfield v. Coryell, 6 Fed. Cas. 546 (1823), the Supreme Court recognized freedom of movement as a fundamental Constitutional right.

It is not a privilege. You shouldn't have to be either rich (private planes have no security) or willing to compromise other rights. We shouldn't have to choose between the right to freedom of movement and the right to be protected from unreasonable search. And yes, freedom of movement applies to all forms of transportation:

For much of American history, the right to travel included the right to travel by the vehicle of one's choice, and courts occasionally struck down regional regulations that required licenses or government permission to travel on public roadways. With the advent of the automobile, however, courts began upholding laws and regulations requiring licenses to operate vehicles on roadways. Constitutional scholar Roger Roots has referred to the forgotten right to travel without license as "the orphaned right."

Don't misunderstand me. I accept requiring driver's licenses as a matter of public safety. I accept requiring a reasonable measure of security for air travel. A metal detector resulted in no invasion of my personal privacy. It's a device which simply detects magnetic substances. I'd be perfectly happy to use a device that somehow detected explosive substances. And we had devices that supposed did exactly that. Remember the chemical sniffer devices that cost millions of dollars? What happened to them? They're gone with no reason or explanation given. Yet now we're spending a few hundred million more dollars on these new machines.

And this leads to another of the many problems with airport security. To use a favorite phrase of one of the CS Department professors: How do you know when you've won? That is, what's your metric for success? How do you know that the actions you've taken made a difference? Without a metric you have no evidence.

So what's the metric used to gauge whether new security procedures are working? The number of successful terrorist attacks carried out against planes? Well, that's been zero since 9/12/2001. So by that metric the security we had last year was perfectly safe. The number of deterred terrorist plots against planes? There's no way to measure that so it can't be used as a metric. The number of terrorists stopped because of airport security? That's also 0. The number of attempted terrorist attacks? This one sounds legitimate but is highly dependent on factors which can't be controlled (a priori efforts of law enforcement, terrorist recruitment levels, etc.) and thus you can't meaningfully compare the value from last year to value for next year.

I'd love to hear an admissible metric. Without one you may as well believe that my terrorist repellent works and just spray each passenger with it before they board the plane. Terrorists will break out in hives! 99.99999% accurate! Prove me wrong!