TSA to allow some small knives in carry-on luggage

Sure, an attacker could kill people with a small knife, but killing and/or threatening passengers and flight attendants will not gain an attacker access to the cockpit. Everyone involved now assumes that a hijacker who gains access to the cockpit will try to crash the plane in to a building, so a significant portion of people will fight to the death against any attempt to enter the cockpit. I suspect everyone who would seriously contemplate hijacking a plane knows this and would not attempt a plan using only small knives.

Cockpit door locks.

I don't like that association in my head.

The 9/11 attacks worked because historically, a hijacked plane would invariably be diverted to some far-flung airstrip and become a hostage situation. Anyone in such a situation understood that their risk of being killed was very low, so long as they complied with the hostage-takers. It took less than a day for passengers to realise that the risks of action and inaction had inverted, as we saw in the case of flight United 93.

The hijacking MO used on 9/11 was a one-time deal. Passengers now understand that rather than being safe so long as they comply with hijackers, they are doomed unless they fight back. As such, a knife on a plane is no more dangerous than a knife on a bus or a train - the attacker might injure or kill a handful of people, but they'll quickly be overwhelmed by sheer force of numbers.

It's for this reason that all subsequent terrorist plots against aviation have been bombs, with the intention of taking down the plane in flight.

Schneier has repeatedly pointed out this systematic failure in security thinking - responding to the last threat, rather than the next.

I understand why they think these knives are still an issue, but I think the training doctrine of "don't obey the hijackers" has changed all that.

Great to hear that pool cues will be allowed again :D. Nothing annoys players more than having to checking their cues especially when they are really expensive.

K-Y Jelly is fine if less than 3 ounces. If you need more than 3 ounces, well, maybe try leaving your hotel room occasionally.

The threat of hijacking is the reason planes get special treatment, but the combination of secure cockpit doors and the perception that hijacking will lead to the deaths of everyone on the plane makes gaining access to the cockpit effectively impossible regardless of the availability of weapons.