http://www.foxnews.com/politics/2011/01/04/napolitano-israeli-style-secu...

But Napolitano said that what is effective in Israel, a nation of 7.3 million, wouldn't necessarily work for 310 million Americans.
Ben-Gurion is Israel's only major international airport. The United States, however, has 450 such facilities. Plus, about 11 million people pass through Israeli airports each year, while 70 times that many passengers go through American airports each year.

Interesting argument by Napolitano. The part about the population is nothing but a sophism: airport are not concerned with people who do not travel, so only the number of travellers should be considered.
Since the 450 international airports are obviously less busy on average (450 for 770 million travellers compared to one for 11 million), it cannot be that it requires too many security personnel, quite the contrary. Each one would require less than 1/5th of Ben Gurion security staff.

The real questions are: does it cost more than using electronic gadgets? does it take more time to scan all rather than scanning only those whose profile is worrying ? and finally, which method is safest, according to statistics?
The last question has already been answered by "underwear bomber". So the rest is basically a question of money. How much is the life of an American worth?