Amazon is now advising users on how to turn off automatic voice ordering after reports that the Amazon Echo can detect keywords from words spoken on the television and mistake certain phrases to be real commands from a user.

On 6 January, it was reported that a six-year-old girl in Dallas, Texas accidentally used the voice-activated Amazon Echo Dot to order a $170 (£136) doll house and a tin of Danish butter cookies. The little girl denied making any purchases, but she did admit that she asked Alexa if she could have some cookies and a dollhouse. At the time, the child's parents had not yet enabled parental controls on the device.

The story went viral on the internet and was covered by multiple US TV news channels, including the CW6 in San Diego. That should have been the end of the story, but then on the morning of Thursday 5 January, news anchor Jim Patton was talking about the dollhouse story and he said, "I love the little girl, saying 'Alexa order me a dollhouse'".

CW6 says that after the news report ended, numerous viewers located all over San Diego started complaining to the TV station that their Amazon Echo devices had tried to order dollhouses after the words were uttered on TV.

The thing is, if your Amazon Echo is in your living room and the Amazon Echo commercial comes on your TV, at least here in the UK, nothing happens when the actors on screen ask, "Alexa, tell me about the Amazon Echo," or "Alexa, put on my Saturday playlist". So what made the Amazon Echo devices in San Diego decide to obey a disembodied voice from the TV?

Interestingly, when Amazon was contacted about the incident, it didn't deny it, but instead advised users to go to the Alexa app and turn off "voice purchasing", as well as setting up a confirmation code that has to be typed in before each order is authenticated.

There have been other cases in the past where voice-activated systems have mistakenly picked up commands with hilarious results. In 2014, a TV commercial where Aaron Paul demonstrated how the Kinect worked made numerous Xbox consoles immediately turn on and launch the Titanfall video game whenever it detected Paul's voice issuing the command on a TV set.

Then there's the YouTube vlogger Master of Luck, who decided to prank people owning Xbox with Kinect by using the gamertag "Xbox Sign Out" and deliberately getting in the way of people who were trying to play Call of Duty Ghosts online.

In this game, players can chat and talk to team members and opponents using voice chat with their headsets, but if users tried to tell the user "Xbox Sign Out" to get out of their way, then the Xbox picked up the words as a command to sign out of the user's account and ended the game.