MIAMI -- Controversial X-ray scanners are set to make their debut at Miami International Airport on Monday.

The new machines show a clear picture of what is underneath passengers' clothing so that screeners can easily detect weapons.

Because the technology allows officers to have a better look at what is inside carry-on baggage, fewer bag checks should be required, thus speeding up the security process.

Some critics, including the American Civil Liberties Union, worry that the technology could be abused.