I wrote here in February about the push and pull over “strip search machines,” also known as “whole-body imaging” and “millimeter wave scanning.”

The question is joined: How do you maintain privacy with a technology that’s fundamentally intrusive? Maybe by using it less. This week, Rep. Jason Chaffetz (R-UT) introduced a bill to limit the use of whole-body imaging.

H.R. 2027, the Aircraft Passenger Whole-Body Imaging Limitations Act of 2009, would place several limits:

• Whole-body imaging could not be the sole or primary method of screening a passenger, and it could only be used as a follow-up to other methods like metal detection.
• Passengers would have the right to opt for a pat-down search instead of whole-body imaging.
• Passengers subject to whole-body imaging would have to be provided information about the technology and the images it generates, on privacy policies, and the right to have the pat-down search instead.
• Images of passengers generated by whole-body imaging technology could not be stored, transferred, shared, or copied in any form after the passenger has passed through the security system.

Most of these protections are already TSA policy, but agency policies are relatively easy to change compared to federal law. Without limitations like this, these machines are on the natural, mission-creepy path to becoming mandatory.

Rules, of course, were made to be broken, and it’s only a matter of time — federal law or not — before TSA agents without proper supervision find a way to capture images contrary to policy. (Agent in secure area guides Hollywood starlet to strip search machine, sends SMS message to image reviewer, who takes camera-phone snap. TMZ devotes a week to the story, and the ensuing investigation reveals that this has been happening at airports throughout the country to hundreds of women travelers.)

So this bill is a step forward, but from a very backwards position. Ultimately, as I wrote before, the solution is to return responsibility for security to the airlines and airports, who are most interested in and capable of balancing all the factors that go into safe travel, including passengers’ privacy, comfort, and peace of mind.