By the numbers

Number of airline passengers killed by terrorists each year (last 30 years): 67
Number of total airline passengers worldwide, last year: 1.5 billion
Dollars spent since 9/11 on increased airport security: 18 billion

Assuming you fly 10 times per year, the rough odds of being killed by terrorists on an airplane in that year: 1 in 2,250,000.
Dollars spent since 9/11 (on average) by every man, woman, and child in America, on increased airport security: 60.

60 bucks might not sound like a lot of money. Cheap insurance, right?

Yes, 60 bucks is cheap. But what do we get for our 60 dollars? Nothing of any demonstrable value, unless you value a false sense of security. And what have we lost? The time spent in line that we could otherwise spend doing business, or on a beach. I'd rather have the 60 dollars back, and the extra hour of each trip, and take my chances.

What would happen if we all just take our chances? We all take far bigger chances all the time, just by driving to work.

Odds of being killed in an auto accident, per 10000 miles driven: 1 in 5900.

If we all had infinite lives, each of us would die about 400 times in a car crash, before we were killed once by a terrorist on an airplane. Maybe we should put those 60 bucks toward defensive driving classes.