Updated Amazon's audio surveillance personal assistant device, Alexa, has acquired an external battery pack called Dox.

The appropriately named portable energy store, made by lifestyle gadgetry firm Ninety7, does not (thankfully) do what its name says.

Instead, says its maker, it offers "up to 10 hours" of extra life for Alexa. The two-inch high battery pack allows an Alexa to be dropped into its embrace, for people who need additional personal surveillance while on the move.

"Even in listening mode, Alexa is running," warns a straight-faced Ninety7.

Doxing is the practice of broadcasting someone's personal details such as their home address, private phone number, credit card details and so on. It is a hostile act normally done in retaliation for some perceived slight – and is quite probably not what either Amazon or Ninety7 wanted to associate with either of their devices.

The voice-activated Amazon Alexa is intended to be used as a digital assistant. Customers shout their demands at the device (play music, make a calendar entry, set an alarm, don’t do that, oh god no), which features an always-on microphone. By default it is triggered when it hears the word "Alexa", though users can customise the precise trigger phrase.

Earlier this year, American police forced Amazon to hand over recordings from an Alexa mic as part of a murder investigation. In turn this event spurred the forensics industry into examining how best to turn Alexas into police stool pigeons.

Another Alexa managed to invoke a further piece of internet-specific naughtiness, swatting, only last week when an unfortunate German chap came home to find his front door locks had been changed. On going to the local police station, he was told that his Alexa had started its own rave – prompting angry neighbours to first bang on his door demanding he turn the music down, and then calling the police when nobody answered. Having been told this, the unfortunate man was then given a €500 fine.

Swatting is the practice of getting police called to a target's house, normally under the false pretence of some violent crime being in progress and requiring armed police to tackle. In America, where the term originated, such police units are known as Special Weapons And Tactics (SWAT) teams, hence the name.

Our review of Alexa, as embedded on an HTC U11 smartphone, found that the thing failed to wake up to its wake word, refused to set calendar invites, and, worst of all, broadcast Dire Straits whenever asked to play a song. ®

Updated at 10:34 on 14 November to add

An Amazon PR rep rang us up to describe this article, at great length, as “irresponsible” and said it “just isn’t accurate”. We are happy to inform our readers that “no data is streamed to the cloud without this wake word. For peace of mind users can electronically disconnect the device using the mute button. No recordings are saved without the user’s consent.” In addition, Bezos’ boys are happy to confirm that in the German case we mentioned above, the user had indeed (as we originally speculated) accidentally activated Alexa as he opened his “third-party mobile music-streaming app”, intending to listen through his headphones.

A fellow journalist from The Times also shared his thoughts on Amazon’s approach to media relations with your correspondent:

I built a more positive relationship with the Tamil Tigers press office, and they kidnapped me. — Tom Whipple (@whippletom) November 13, 2017