I find it silly to assume that the WTC used their bare hands when on both the other planes items were used such as box cutters and knifes.
Just because those hijacked on the 2 WTC planes didn't get a chance to call others and report what was going on does not mean no weapons were used. ALso the victims on both WTC planes really had no idea what was going on. It all happened so quick.
I do find it hard to believe that a gun was aboard either WTC plane as well.
If it's the latter scenario, then the only people who did their job that day were the $4.50 an hour baggage handlers, the people who were blamed and lost their jobs because of 9/11, while the trillion-dollar "intelligence" agencies failed completely, with no high level resignations.
On the other hand knives are plausible too since trying to get guns aboard the planes is a riskier proposition.
In any case I doubt that it's all that relevent. No system, no matter how good, can stop all possible attacks. I think that many of the attempts to find fault with the government are based on the faulty premise that the government can make us perfectly safe. They never could do that. Unfortunately many of the things government is doing now, like confiscating fingernail clippers and spying on American citizens, will founder on the same foolish premise.