Florida's busiest airport will be the first in the countryto require a face scan of passengers on all arriving and departing international flights.Officials there say all passengers, including U.S. citizens, will be scanned.Orlando International Airport's expected policy worries some privacy advocates.They say there are no rules in place for dealing with the information taken from the scans.Also, there is no system for assisting a passengerwho is wrongly prevented from getting on an airplane.Airports in Atlanta, Boston, Chicago, Houston, Las Vegas, Miami, New Yorkand Washington already use face scans for some departing international flights.However, they do not scan all international travelers like the airport in Orlando plans to do.The image from the face scan is comparedto a Department of Homeland Security biometric database.The department has images of people to confirm travelers' identities.Harrison Rudolph is with the Centeron Privacy & Technology at the Georgetown University Law Center.He said U.S. citizens at these airports can refuse to be scanned.But the agency does not seem to be letting people know they can refuse, he noted.Jennifer Gabris, a spokeswoman for the U.S. Customs and Border Protection Agency,wrote the Associated Press about the policy.U.S. citizens at the Orlando airport can refuse to be scannedif they do not want to provide their photograph, she wrote.However, a notice about a possible rule change for the programsays "U.S. citizens may be required to provide photographsupon entering or departing the United States."Rudolph said the Orlando announcementmarks an increase in the face scan program."We're not talking about one gate," he said."We're talking about every international departure gate,which is a huge expansion of the number of people who will be scanned.Errors tend to go up as uses go up."Orlando International Airport had about 6 million international passengers in the past year.Rudolph said he is worried about the face scans' exactness.Some research shows they are less exact with racial minorities, women and children.Some researchers say this is because pictures used in the face-scanning softwareunderrepresent minorities, women and young people.Last month, two U.S. senators sent a letter to the Department of Homeland Security,which is home to the border protection agency.Senator Ed Markey of Massachusetts and Mike Lee of Utahurged that official rules be put in place before the program is expanded.Official rules, the senators explained,would help Americans understand and accept the program.They noted that this is important because it would affectevery American leaving the country by airport.