On a serious note, it's a reminder to remain vigilent. I'm guessing that it's probably not much more difficult to get weapons on a plane than it was before 2001. The big difference now is that people on planes have a different mentality and will no longer just obey and expect everything to work out (like it used to). See someone trying to light something? Kick the living s**t out of them. A box cutter would tear me up, but they'll have to get through my carry-on bag first.
Carry-on bag or grab a blanket/pillow to cover your hand or arm. A razor knife won't cut much if it's not moved in a slicing motion and the point will only penetrate about an inch. If it's a pocket knife, it may not do much, either and many people who carry a knife really don't know how to use it effectively.
Anyone caught trying to do something like this should be ground into a fine paste.
If a weapon gets through the security checkpoint, I think the person on duty needs to be held responsible. Period. None of this "But they only make $X/hour crap- people need to do their job, regardless of the pay. Justifying their performance because they think they're underpaid is just a bad work ethic.
