Max - you were talking about arming passengers.
if we, the pilots, cabin crew and fare-paying passengers were permitted to carry on to aircraft certain household items such as pen-knives, nail-clippers and syringes which could, in extremis, be used as offensive weapons. I'd personally feel a lot safer knowing most passengers were thus "armed" in the event that a group of nutters on board decided to try to take over the aircraft. At least we've got something to fight with.
Personally I would rather have everything taken off passengers then there is nothing to worry about in the first place.
And yes I do agree with you that taking a pen knife off a college then giving it him back in a brown ebvelope for safe keeping is a bit of a Homer Simpson. I don't think they had their 3 weetabix that morning.