Considering the avalanches of security alerts that are constantly being received, I don't really see how things could have been so much more secure. Picking out the genuine alert amongst a sea of false alarms can't be easy. I know over the last few decades, we have been alerted to special threats when they are deemed serious enough. This would have been just another unlikely warning. If the CIA was 5 times the size and monitoring mobile phone calls and faxes and landlines all over the world, people woould be shrieking about human rights and 'how dare Dubbya etc!!'. It's a 'you can't win situation!'. Was it reasonable to expect 4 hijackings in one day with tremendous loss of life? I don't think so. That the genuine warning was buried in a sea of alerts is just tragic, but I would think unavoidable.