They're supposed to make flying safer.
But new body scanners, now being installed at airports around the country, are causing some controversy.
The Cincinnati-Northern Kentucky International Airport is one of the first airports in the country to get the machines.
Travelers definitely have an opinion on the scanners, which are very revealing.
"In a presentation I was looking at, it says it would be as overt as being in the shower when they are looking at you," Airport Worker Shahied Rashid said. "So I didn't like a public shower."
The machines are controversial because it would allow security officers to see beneath a passenger's clothing to search for hidden items such as explosives or weapons.
Passengers will have the option of accepting or declining a body scan at the airports where the machines will be in place.
Those who decline will have to walk through a metal detector and will have to have a pat down by officials.
The new machines are being bought with money from the federal stimulus package.
Blue Grass Airport officials say we could see them there some time next year.