I accept that airline security is the responsibility of everybody who flies. However, this story seems to take it a bit too far. Said a representative of the Canadian Air Transport Security Authority:

The lesson to be learned out of this, and the message to other passengers is, to really be aware of what you can and cannot bring onboard with you, because even something as innocuous and innocent as a Swiss Army Knife, which is a prohibited item, can create enormous delays and headaches.

The reason this man was able to board an airplane carrying what later turned out to be a multitool was security didn't stop him in time. Now, yes, he should have known that he wouldn't be allowed onboard with a knife, but maybe he just forgot. I almost have; if putting on a Leatherman with your belt and pants every morning is part of your routine, you forget that some people might take a dim view of you carrying the tools of your trade with you. Marketers carry Blackberries; I carry a Leatherman Super Tool. The people who fell down on this were that woman's co-workers - the ones who should have stopped him before he cleared security. How is it his fault that somebody else screwed up on their job?  The lesson to be learned is not that you need to be really aware of what you're carrying (we already learned that, thank you very much), but that the Transport Security Authority blames other people for their mistakes.

Reason number 10,542 why I would rather have three root canals in a day instead of flying.  (Actually, I've had a root canal, about 3 years ago; it was much less painful than flying Air Canada from Pearson.  At least dentists don't make you wait in line for 3 hours before they deign to seat you, and the seats are more comfortable.)