The Transportation Security Administration says passengers then have the option to either go through the advanced screening booth that does the full body scan, or to get a pat-down.
The pat-down used to be performed with the back of the hand only, and it used to be less invasive.
Recently, they changed the pat-downs so they use the palms of their hands for everything but two areas. The private areas for both men and women largely were not patted down before, but that has changed.
They also now look along the inside of the waist line of pants on women and men.
Andrew Welch is a law student at the University of Denver. He just completed an article to be published in the next few weeks about full-body screenings and TSA procedures.
He says TSA is on a very slippery slope and wonders at what point they realize they may have gone too far.
"The question is: 'What's the next step?' 'How far can we go?' 'Millions of innocent people strip naked?'" Welch said.
The TSA told 9NEWS on Thursday that for those feeling uncomfortable with the full-body scan - the person seeing the images never sees the person being scanned. They are in a separate room and the images from the scan cannot be saved.
As for the pat-downs, a TSA screener told 9NEWS he is just as uncomfortable with it as passengers are.
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