NEW : ACLU says passengers ' detailed images violate privacy , not dignity . In addition , the scans will have a `` modesty filter '' to blur out faces , and no images will be saved . New machines use radio frequency to scan passengers for hidden objects . They 'll be used on passengers selected for secondary screening . FBI says blurred image , remote location of passengers protect privacy .
NEW : ACLU says passengers ' detailed images violate privacy , not dignity . New machines use radio frequency to scan passengers for hidden objects . They 'll be used on passengers selected for secondary screening . FBI says blurred image , remote location of passengers protect privacy .