Amazon Echo and the internet of things that spy on you

Amazon's Echo is a robot that sits in your house and listens. The virtual personal assistant can be summoned into action by saying its name, Alexa, and will then act on commands, like ordering a dollhouse and cookies when asked to do so by a too-clever kindergartener. And because it works by listening, Alexa is an always-on surveillance device, quietly storing snippets of information. Which has placed a particular Echo unit in an uncomfortable role: possible witness to a murder.