Inaudible ultrasound commands can be used to secretly control Siri, Alexa, and Google Now

Is your digital assistant taking orders behind your back? Scientists from China's Zheijiang University have proved it's possible, publishing new research that demonstrates how Siri, Alexa, and other voice-activated programs can be controlled using inaudible ultrasound commands. This provides a new method of attack for hackers targeting devices like phones, tablets, and even cars. But don't get too worried -- the technique has a number of key limitations that means it's unlikely to cause chaos. U...