How to detect a terrorist: International travelers are under the microscope.
One U.S. resident and his family are from Yemen and have faced a gauntlet of questions.
"If you don't do anything wrong you don't have to worry about nothing, that is my final answer," said a Yemeni man at Los Angeles International Airport Tuesday.
"I am from Armenia and we have been racially profiled in Russia, actually," said another man at the airport.
Is stereotyping OK? Aviation-safety specialist Barry Schiff has long been an advocate.
"We have not been attacked by Swedish girls, for example," said Schiff. "We've been attacked by Muslim men."
"It is the only effective tool to actually identify terrorists," said Amotz Brandes, director of Chameleon Associates.
Brandes is a security specialist. He spent years with EL AL Airlines, an Israeli company, which has a record of deterring terrorists. But he says racial profiling is wrong-headed. Instead, he pushes "predictive profiling." It involves first knowing the methods of the attackers, from how they conceal bombs to how they try to blend in.
"How they build cover stories, how they steal identities," said Brandes.
Armed with this information, an interviewer talks to each passenger.
"People think, 'Well, do we have time to do that?' Yes, we do. We do have time. People stand in lines," said Brandes.
He demonstrates why racial profiling doesn't work: Kozo Okamoto headed an attack at an airport in Israel. A Palestinian group hired the Japanese man because he didn't look Palestinian.
The Council on American-Islamic Relations points out other terrorists who buck the racial profile.
"Adam Gadahn, he would not fit the profile of a stereotypical Muslim. Look at Jose Padilla. His background was Hispanic," said Munira Syeda, spokesperson for the Council on American-Islamic Relations.
As for improving screening technology, Brandes says: "I don't know of one incident where a terrorist was found first by looking for the explosives, the weapons, and then looking for the intent."
One more reason to discourage racial profiling: Muslim civil-rights advocates say it alienates Muslims, the very people the government depends on to gather intelligence.