"What good does it do me, after all, if an ever-watchful authority keeps an eye out to ensure that my pleasures will be tranquil and races ahead of me to ward off all danger, sparing me the need even to think about such things, if that authority, even as it removes the smallest thorns from my path, is also absolute master of my liberty and my life; if it monopolizes vitality and existence to such a degree that when it languishes, everything must also sleep; and when it dies, everything must also perish?" - Alexis de Tocqueville
"Here," says government, "let me pry into your business. After all, it's only for your protection! If you have nothing to hide then you shouldn't have anything to worry about."
Wrong answer. If you have nothing to hide, then why should you be illegally searched, hassled, and harassed? Obviously if you are not a criminal then the government will gain nothing by harassing you. So, what's the point?
Let's analyze this just a bit more. If you were a criminal mastermind, why would you bring such nefarious items as too much money onto a plane? If you'e planning something evil, cash is a horrible choice. So, there goes that argument. Also, if you were a madman, would you really do things so obviously stupid as put weapons, etc, into a metal box in your luggage? I think you might try to be just a bit more clever than that. Lastly, although certainly not least, why should we be searched against our fourth amendment right not to be searched without probable cause? Is getting on a plane sufficient evidence that you are a terrorist? I certainly think not.