The product description does a really poor job of explaining what this is to someone who has never heard of it. It's just a wink-wink-nudge-nudge reference to s

The product description does a really poor job of explaining what this is to someone who has never heard of it. It's just a wink-wink-nudge-nudge reference to some DEFCON talk. Can someone explain what this is? Is it a hardware keylogger?