The current TSA measures create an even greater harm: loss of liberty. Airports are effectively rights-free zones. Security officers have enormous power over you as a passenger. You have limited rights to refuse a search. Your possessions can be confiscated. You cannot make jokes, or wear clothing, that airport security does not approve of. You cannot travel anonymously. (Remember when we would mock Soviet-style “show me your papers” societies? That we’ve become inured to the very practice is a harm.) And if you’re on a certain secret list, you cannot fly, and you enter a Kafkaesque world where you cannot face your accuser, protest your innocence, clear your name, or even get confirmation from the government that someone, somewhere, has judged you guilty. These police powers would be illegal anywhere but in an airport, and we are all harmed — individually and collectively — by their existence.
Source: Essays: Economist Debates: Airport Security – Schneier on Security