A sign explains the procedure for going through the millimeter
wave machine as passengers wait in line at a security
check point at the Salt Lake International Airport in
Salt Lake City, Utah, on March 10, 2009.
By Michael Grabell, ProPublica
Look for a PBS NewsHour story on X-ray body scanners, reported in conjunction with ProPublica, to air later this month.
On Sept. 23, 1998, a panel of radiation safety experts gathered at a Hilton hotel in Maryland to evaluate a new device that could detect hidden weapons and contraband. the machine, known as the Secure 1000, beamed X-rays at people to see underneath the ir clothing.