Behave yourself! Your smart digital devices at home may be watching or listening to you.

In what maybe the first case of its kind, police investigating a murder case in Bentonville, Arkansas, issued a warrant to Amazon.com to turn over audio and other records from an Amazon Echo digital assistant in the home of James Andrew Bates after Victor Collins was found dead in Bates' hot tub last year, tech news website The Information reported on Tuesday.

Bates was charged with murdering Collins, according to court documents.

Echo is an always-on digital assistant in the shape of a speaker developed by Amazon.com. It is capable of doing many tasks, such as answering questions, calling a Uber, ordering pizzas, playing music and audiobooks, reading news headlines, providing weather, traffic and other real-time information.

Police twice asked Amazon for audio from Bates' Echo, and Amazon refused both times to provide the data.

"Amazon will not release customer information without a valid and binding legal demand properly served on us. Amazon objects to overboard or otherwise inappropriate demands as a matter of course," the company said in a statement.

However, local media said the company did give prosecutors information about Bates' account and purchase history.

According to court documents, police took Bates' Echo and extracted information from it.

In addition, police found that readings on Bates' smart water meter recorded heavier than normal use of water in Bates' home at the night of Collins' death. Investigators alleged that the extra water was used to wash away evidence off the hot tub and patio, according to court documents.

The case is just an example of the ongoing trend of the Internet of Things (IoT), a network of connected smart devices that track people's locations, listen to their words, learn their preferences, and monitor their online footprints.

Amazon said Tuesday in a news release that Echo and the smaller Echo Dot were the best-selling products across its platform this holiday season, with sales up over nine times compared to last year's holiday season, and millions of Alexa devices were sold worldwide.

With the booming and popularization of IoT devices, the concern of privacy at home and at work has become more and more prominent.

Users need to be aware that all Internet of Things devices might eventually be implicated in criminal investigations, Marc Rotenberg, president of the Electronic Privacy Information Center, told USA Today.

"There should be clear legal standards established for law enforcement access. And manufacturers should adopt techniques for data minimization and data deletion. Devices that retain data will be targets not only of law enforcement officials but also criminal hackers," said Rotenberg.

source: Xinhua