I think most of the post 9-11 security measures are absolutely useless. All they do is make people think the government is doing something. All of the airport security and security at "events" only works for people that follow the rules, and the bad guys don't follow the rules. I sincerly doubt that anyone could hijack a plane today with a pair of nail clippers or a mini-pocket knife. Yet we are paying thousand of airport security screeners to confiscate these items everyday. I am not saying that there should be no screening, obviously that would invite problems. But a little more realism would be nice.
I live in the DC area. For the 4th of July, they put up a little temporary fence and have metal dectors to get on the Mall grounds for the fireworks, etc. So all of the law abiding people wait in long lines and deal with restricted movement all day long. While if someone really want to disrupt thing all they have to do is drive a car thru the fence or hop the fence between two security people when one of the guys who is hot, sweaty and tired is looking at the cute girl walking by.
A lot of money is spent giving the illusion of security. Visible measures to make the masses think our government is keeping us safe. I think most of it is wasted. We should be spending more on the measures to shut it down before it happens. That includes covert measures, humanitarian aid and support, and education (both in the US and overseas).