I thought I spelled it out pretty clearly, but evidently not. Maybe I will try again...
Terrorists can take over an airplane using everyday items that will not be confiscated at security. They will not carry guns or knives etc because they know there is a good chance of them being taken away. On 9/11 for example the crims used boxcutters that were legal for carriage at the time. In the future they will use other items that are not banned. If you are in security you will know what I mean.
This means that even if every gun and every knife and every nailfile is stopped at the security point it will not prevent a terrorist from attacking the airplane once it is in the air. I gave several examples of this, with one example, in Algeria, of the airplane almost being taken when a group of men broke into the flight deck and beat up the pilots using only their fists. If they had closed the flight deck door behind them they would have been successful, but as it was the cabin crew and pax managed to stop them.
Should security be abandoned then, as useless? No, of course not, but the standard used in most parts of the world is quite satisfactory. Unlike in the US, they do not find it necessary to single out aircrew for special treatment; everybody gets the same or if they have a good identity check going aircrew get preferential treatment, not because aircrew are 'special' but because holding up the crew will delay the flights. There is no "random" searching, and only if you set off the detector or have something suspicious in your carry on would you attract attention. Or if you are acting weird. In this way security is not a bottleneck or something to be feared. It works, but at the same time it is not 100 percent. It cannot be that, ever (the only weapon used for an attempted hijack recently was a pocket knife and that was on an El Al flight, supposedly the safest in the world with the most stringent security).
If you are on the receiving end it sure feels like you are being treated like a criminal, with no rights. Even on the road you are entitled to respect from the police if they pull you over, but when you try to get on an airplane you are considered to have given up all rights to privacy and respect, and why should I have to be subject to this? I am not a criminal, and neither are the almost 100 percent of others who want to fly. So there are some bad guys out there, why not concentrate on them? If you cannot identify them, work out how to do that, without getting in my face. Passenger loads in the US are down 15-20 percent, not because of a fear of flying, but because of the way they are treated at the airports.
And when you know that ONLY passengers and crew are subject to security, with the thousands of airport workers free to come and go as they please, you know that the authorities have set up a system that is designed to APPEAR effective, but is almost worthless.
Here's some proof for you to ponder. There have not been any bombings of airplanes in the US since 1962, yet the govt made a real effort to get bomb scanning xray machines installed at all airports before Dec 31 last year, despite there being no really effective machines available. The ones they use have a 20-30 percent failure rate (false positive). Imagine the cost, and who got the kick back?
Go look at how they work. Beside every machine, usually set up in the concourse, with thousands of passengers milling about, is a table where the bags that fail ( a lot of them) are manually searched by someone with a pair of rubber gloves. Remember, he is searching for a bomb. If there was a bomb there, how would it be set off? That's right, by handling it! This is the same airport that will evacuate a whole terminal for hours if a bullet is found on the floor, or a scanner found to be unplugged, yet they will allow a man with no explosives training fiddle and manhandle the contents of your bag (and since all bags must be left unlocked the owner might not even be there...does this suggest anything?). When he sets off the bomb that the machine has told him is likely to be in the bag, thousands will be in the blast area.
So why would the govt allow this insanity? Simple, they know there is no bomb. Again, the whole setup is for show. And incidentally to grow government and take away peoples' rights, which was the main intent in the first place.
None of us are against effective and reasonable security, just knee jerk stupidity. You may feel you are "just doing your job", but if that job is ineffective and is destroying the whole airline industry, don't expect those of us who have to put up with it to applaud you.