Looks like the French aren't the only ones who misplace things while checking secutrity at airports - seems an American security team misplaced a fake bomb recently. It went through the machine, and triggered an alarm, but noone searched it. Whups.

I'm curious as to the percentage of attempts that these slip-ups represent. An occurence such as this could make for ratings in a news segment, but if it's 1 out of 10,000, 100,000, or more, then perhaps it would be a little less newsworthy. What is the fault tolerance on other things in which we trust our security or life? For instance, is it less or more likely that a plane will crash due to pilot or mechanical error?

I think the point is more like the point being made with the missile defense system - when security knows there's a test going on, they should be even more likely than usual to stay on top of these things. I'm fairly certain that in both the French and American case, the luggage wasn't supposed to enter the system at all, save for a small portion, and then it was supposed to be pulled back out.

As for the question of failure rates, the point there I think is that any failure rate higher than zero is, in the world these people live in, potentially a plane blown up. Now, the fact is that security could probably be a lot more lax and it wouldn't matter, but given the way everyone has been told time and again that there's a terrorist behind every tree, these slip ups seem quite important.