I wouldn't use this, but this is cool. At first I thought it was using microphone to detect which side the smacking sound was coming from, but since others have

I wouldn't use this, but this is cool. At first I thought it was using microphone to detect which side the smacking sound was coming from, but since others have pointed out, I didn't know harddrive heads have such sensors and can be accessed using programming language. It's probably suitable when you want to have an emergency button to destroy/encrypt/close all super-confidential information when someone's approaching and you don't have enough time to type/click anything, just smack!.