I consider myself a civil libertarian.  Central to my political philosophy is that the purpose of government is to protect individual liberty and property — not to impose or enforce an agenda, whether it be "family" values or "progressive" values; these are things that should be left to the realm of persuasion, not coercion.  I consider much of the so-called "Patriot Act" to be an unnecessary intrusion on liberties in the search for security; various parts of the act were expansions that the government had been trying to obtain for years.

All that said:  why in the world do we not have more full-body X-ray machines at airports?  I'll even grant voluntary "opt-out" provisions (with an opt-out that would result in a physical search).

Civil libertarians are barking up the wrong tree in fighting these security devices — tools that are available now, and would make sneaking explosives onto planes more difficult by degrees of magnitude.  The concerns are valid:  as reported here, the full body scans leave little, if anything, to the imagination.  But isn't that the point?  If a potential terrorist is going to hide explosives, isn't he (or, eventually, she) going to hide it in the most difficult-to-find nooks and crannies?  The Christmas Day bomber, Umar Farouk Abdulmutallab, hid the explosives in his underwear, and obviously with good reason:  he was successful in getting past security with a deadly weapon.

Capitalism is based on voluntary exchange, but purchasing a service from a private company — in this case air travel from an airline — is not a fundamental right.  If a person believes that air travel is too inconvenient, or too cramped or too policed, he has the right not to fly; there are certainly other modes of transportation available.  No person would be subject to a "search or seizure" without prior knowledge of the rules of the game.

A sensible policy would be to require either a full-body scan, or, if preferred, a manual examination by a specially-trained security officer prior to boarding any flight.  Personally, I would prefer that the airlines initiate such a policy on their own as a competitive advantage (wouldn't you rather participate in a flight on which you had a near sure chance that no explosives were aboard?), but given the special nature of airline travel and the fact that commercial airline companies tend to be either interstate and/or international in scope, I believe government action is appropriate if necessary.  The Transportation Security Agency (TSA) could work with civil libertarians to ensure that privacy is protected as much as possible.  Already, there are software tools to blur the faces of the scanned individuals, and the images should be destroyed as soon as possible following the scan.

That's not to say that distrust of the government on this issue is unfounded; post-9/11, the government took many steps in the name of security that truly did limit individual liberty, and, to add insult to injury, didn't improve safety and security.  The famous Ben Franklin quote about sacrificing liberty for security (and leaving oneself with neither) certainly applies to many government actions.  Not so with this.

The basic purpose of government is to protect the life, liberty, and property of its citizens.  I certainly believe that government consistently steps outside these bounds needlessly, overwhelmingly, inefficiently, and intrusively on a daily basis.  A little inconvenience, however, in exchange for a huge benefit is a net positive in this particular case.  Let's put modesty aside (and perhaps do a few more situps) and implement a sensible scanning policy for flights into and within the US.