Oh, look! The quadrotor drone has taken a break from its death-chopper training regimen to play us a Christmas tune. It wants to make friends! And if you believe that enough to let your guard down, you're probably already dead.
This particular quadrotor's name is "Echo", which presumably hints at some sort of sonar capability to run you down even after the flying robot swarm has blacked out the sun. But enjoy your "Jingle Bells", humanity! Enjoy your hacky sack games! Just remember that the cuter these things get, the harder they'll be to take down. [Engadget]