“TSA has certified certain foreign airports as maintaining security measures comparable to those of US airports. Travelers flying into the US from these airports are not put through additional security when they arrive. Nevertheless, security at these airports does notroutinely perform pat-downs on travelers with artificial joints. If the TSA itself has certified that security at these airports is equivalent to that of US airports, how can these searches be essential to safety? The official purpose of TSA security checkpoints is to prevent passengers from carrying weapons and explosives onto airplanes. Why would a terrorist use someone guaranteed to set off a metal detector?”
http://www.millersmoney.com/money-weekly/your-artificial-knee-might-get-you-groped