The smart home has ears, and it can't keep a secret

There are many reasons why people might want to buy one of Amazon's Echo devices for their home -- for example, to stream music from the Internet, hear weather reports, control Web-connected appliances and order paper towels. They probably don't buy an Echo to supply evidence about themselves to the police. That may become part of the package, however, because of the way Amazon enables people to control an Echo with their voice. The device has a microphone that's always on, waiting for a "wake word" that causes it to record and send the user's request to Amazon's servers online. There, the speech is analyzed and converted into a command (e.g., "Alexa, set a timer for 15 minutes").