Target - control a motorized Airsoft target

Here's a simple program that uses a Piezo element as a sensor to trigger a servo to actuate your target when hit, then reset to it's original position.

http://builderbrush.com/downloads/arduino/Target.pde

uses a Piezo element as a sensor

Is the piezo part of the target? I'd've thought they'd be too fragile, even for Airsoft.