Think of the practical implications of what many of you are suggesting. A lot of great ideas and inventions never make it off the ground because they can't be made profitable. If every invention had to be made "terrorist proof" (which is probably impossible anyway), it makes it that much more difficult to be profitable.
Take planes and buildings as an example. Austim's suggestion that planes have pilot over-ride systems is a good idea, and it's probably not beyond today's technology. But do you really want to pay $200 more for your plane ticket? Think of the implications to the airlines. Less people would fly, and, in the long run, more airlines would face UAL-like financial problems. The same goes for buildings. Should we make our large structures airplane proof? Oh, and by the way, when you make your building airplane proof, don't forget to consider planes that will be developed 50 years from now (or whatever you expect your building lifetime to be). It's border-line ridiculous!
These comments allude to a bigger question, indirectly posed by ivymike. Do we really want terrorists to change our way of life? Do we want technology development to be partially controlled by terrorists?
Think of all the inventions already out there that are convenient to terrorists. One of the most important things for a terrorist organization is communication. Telephones, cell phones, email, internet, cassete tapes, and video tapes make terrorist communication more effective. Does that mean we should try to make these technologies terrorist proof?
Crooks, criminals, and terrorists have been utilizing the latest technology throughout history, and they will continue to do so. It is unreasonable and impractial to try to put a complete stop to this.
Having said all this, let me concede that there are obvious exceptions. Technologies developed specifically for weapons applications are one example. But, because of the very nature of those technologies, they are developed with countermeasures and other advesary-related issues in mind. Other technologies include encryption technology and GPS technology. In most cases, the government already regulates (and many times is the chief developer of) these technologies.
I would also like to make some comments on the ethical canon that so many of you are referring to, i.e., "Hold paramount the safety, health and welfare of the public." This sounds good in theory, but is NEVER practiced in reality. I recently took a safety course, and the first thing the instuctor said was, "Everybody likes to say 'safety first,' but, in reality, safety is usually last." The bottom line is that good engineers and companies
strive to make a product as safe as possible with the available budget. Then, in the end, a decision must be made as to whether the design is "safe enough." But money always determines how safe you can make a product. Take cars and airplanes as an example. Everybody knows that both cars and airplanes could be safer than they are. Furthermore, people are well aware that some cars and planes are safer than others. Think about what that implies. Take an "unsafe" car (one that performs poorly in crash tests, braking, etc. vs. other cars). At some point, a designer said, "Look, we could make this car safer, but then our price tag would go up to $25k. We want to sell this car for $15k, so we're not gonna do it." Are they holding public safety paramount? Absolutely not. Are they being unethical as a result of that? Probably not (it could be argued, I suppose).
With safety, "acceptable risk" always comes into the equation. The same goes with the development of technologies that could be used in harmful ways. At some point someone has to decide if the benefit from the intended use of the technology outweighs the potential harm from unintended use. The risk will always be there.
My (long) two cents,
Haf