Can one concretely say that the increased security measures are any more effective in stopping terrorism? I think that the jury is out on that one. Sure more potential hijackers have been reported to be stopped, but that could be media hype, a larger definition of what is considered a terrorist act or previous suppression of figures by the government or airlines...all plausible explainations of increased numbers of people being stopped under new procedures, but not related to the procedures themselves.
Also, couldn't the fear-mongering, xenophobia and arrogance that these new measures stem from and that charecterises post-9/11 america also cause an increase in the number of potential terrorists? So there would be a higher number of terrorists being caught with or with-out the new procedures.
I think most people want to feel safe on a flight, but I also want to feel safe in my own skin and everyday life and I want that for everyone. I see these procedures as just another example of the errosion of personal freedoms and dealing with the symptoms of terrorism and not the causes.